# Pioneer RCA preout noise prevention



## cam2Xrunner

For those who have ever had noise issues with their 880PRS or other deck, this post might help.



> as far as the noise issue with the RCA's... i've seen it a million times. the very last thing you want to hook up with these units, is the RCA's at the head unit. too many times i have seen people hook up the RCA's at the head unit first, and then ground the center pin of the RCA's accidently. even with the unit unplugged, the capacitors hold a small charge, and that small charge can take out the final RCA output transistors, and also the caps themselfs.
> 
> the result is, noise. sometimes serious noise, that the unknowlegeable "fix" by grounding the RCA sheilds... but some noise still remains until the transistors and caps are replaced.
> 
> bottom line, to avoid this, make all connections of the system, and the very last thing to do, is plug the RCA cables into the head unit. since the 860/880 has a detachable RCA harness, best to leave the harness unplugged until last.


He's an EE and does repairs, and new product R&D for Pioneer, Alpine, JL, etc.


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## chad

Well, I was under the impression that it popped a Pico fuse. Regardless to touching the pin to ground it's still a ****ty implementation. I've made MILLIONS of connections, even ones that naturally touch ground (shield on a 1/4") and have NEVER popped an output stage, or input stage for that matter on an ocsasional pahntom powered hot patch.

Poo Poo to pioneer for that output design, it's poor and that's undisputed.

Good call on the caps though I wrote this in a PM to a member which may give a bit of insight as to why this happens.



> Generally the problems arise after reading this.... "All I did was hook it up and un-hook it" there is no concrete answer of any amplifier grounding scheme that causes the failure but more of an issue of connection/disconnection. I would suspect even sometimes hot-swapping...... Bla Bla Snip
> 
> 
> A schematic would certainly give me a "yep this is how it wants to run" and I find it pretty awful that pioneer is keeping so hush about this and not telling us WHY this is happening. So for now I recommend complete power disconnection during patching and certainly no "hot swapping" with everything powered up.
> 
> The output is more than likely cap coupled, I was experiencing issues while trying to run balanced input with this because the caps would develop a charge then discharge during on/off or mutings. This discharge of the caps during connection is what could be causing the pico fuse to blow, a cap, no matter how big, will try to deliver an infinite amount of current during a shorted discharge and will draw an infinite amount of current while charging with no current limiting. I'm thinking this paired with an under sized protection scheme (most heads just use like a 0 or 1 ohm FP 1/4W resistor) is causing the issues, which, are blown pico fuses. A simple fix for a service center wanting to make a quick buck unfortunately.


So does anyone with a manual want to elaborate on a hook-up scheme from pioneer? Is it power last or RCA last?


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## kyheng

For safety, to prevent noise on Pioneer HUs, power is the last to connect, no hot swapping(change to get noise is very high)


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## Lightninghoof

This is somewhat unrelated, but I've had too many Pioneer/Premier HU's fail over the past 15 years to give them any more of my money. From faceplate backlights failing, to whine/ground issues that pop up out of nowhere, to CD read errors, etc. Just feels like disposable car audio to me.

It's funny, I have home audio equipment that has lasted 20+ years and still going strong, but car audio equipment won't last for more than 2 or 3 years without malfunctioning, and I baby this stuff. Your average teenager probably gets 6 months to a year of use out of it, if he is lucky.


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## MidnightCE

Lightninghoof said:


> This is somewhat unrelated, but I've had too many Pioneer/Premier HU's fail over the past 15 years to give them any more of my money. From faceplate backlights failing, to whine/ground issues that pop up out of nowhere, to CD read errors, etc. Just feels like disposable car audio to me.
> 
> It's funny, I have home audio equipment that has lasted 20+ years and still going strong, but car audio equipment won't last for more than 2 or 3 years without malfunctioning, and I baby this stuff. Your average teenager probably gets 6 months to a year of use out of it, if he is lucky.


your house doesn't constantly vibrate and jar, or subject the stuff inside to 130+ degree temperatures. Or require as much stuff to be packed into one little space.


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## Boostedrex

MidnightCE said:


> your house doesn't constantly vibrate and jar, or subject the stuff inside to 130+ degree temperatures. Or require as much stuff to be packed into one little space.


Not to mention that the power supply for your home gear is constant and doesn't fluctuate.


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## chad

Boostedrex said:


> Not to mention that the power supply for your home gear is constant and doesn't fluctuate.


I have my own 25KVA pole pig and it's still all over the place. I couldn't imagine sharing with others like I used to, it was REALLY all over the place then.. The only thing you can count on with home AC is that it will always be spot on 60 cycles.


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## Lightninghoof

It still blows balls to purchase a $600 HU, baby it, and only have it last for 16 months.


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## cam2Xrunner

chad said:


> Well, I was under the impression that it popped a Pico fuse. Regardless to touching the pin to ground it's still a ****ty implementation. I've made MILLIONS of connections, even ones that naturally touch ground (shield on a 1/4") and have NEVER popped an output stage, or input stage for that matter on an ocsasional pahntom powered hot patch.
> 
> Poo Poo to pioneer for that output design, it's poor and that's undisputed.
> 
> Good call on the caps though I wrote this in a PM to a member which may give a bit of insight as to why this happens.
> 
> 
> 
> So does anyone with a manual want to elaborate on a hook-up scheme from pioneer? Is it power last or RCA last?


Here's another reply he typed afterwards.



> completely forgot to address the ground problem issue... what people refer to the microfuse.
> 
> i've also seen this happen. a lot of times, when people dont have a good ground to their amps, or in some cases, forget to connect a ground altogether, the amp trys to get ground through the RCA cables. after all, with no main ground, the only path to ground is the RCA cable shields through the head unit.
> 
> this will take out the microfuse, which results in a lot of noise.
> 
> is it a bad design ? well... yes, and no. i've had Alpines, Eclipses, Clarions, Kenwoods, etc, etc, that have had this done to them, and the damage suffered is always worse than on the Pioneers.
> 
> on the other hand, they do seem a little overly sensitive. safe thing is to always make positive that your amps are properly grounded before turning the system on.


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## solacedagony

chad said:


> So does anyone with a manual want to elaborate on a hook-up scheme from pioneer? Is it power last or RCA last?


*As per a yellow paper saying "Warning" on it:*

_"Always remove a connector from the (-) battery terminal before beginning any connection or installing work.
...
When installing this unit, always connect he ground wire first. Ensure that the ground wire is properly connected to metal parts of the car's body. (Fig.3)
...
When connecting the power amp (sold separately) to this unit ensure that the ground wire for the power amp is properly connected to metal parts of the car's body. Connect the ground wire of the power amp with a different screw from the one you used to connect the ground wire for this unit or any other device. Should the screw for the power amp's ground wire loosen or fall out, it may result in this unit emitting [magic] smoke or malfunctioning. (Fig.3)"_


So they're saying to not use a common ground and to hook up the ground wire FIRST. What about if your ground wire is on a harness? Constant, memory and ground will all be connected simultaneously.


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## Nathan P

I'd say make sure the batt is disconnected and you'll be fine. I didn't do this, but I guess I got lucky. I always disconnect the batt when I do stuff, guess I forgot this time  good thing it turned out okay, that'd be an $$ mistake.


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## dalinkwent

So is there any write-up or anything of that nature that shows how to fix this problem? I only ask because unfortunetly I am one of the many that has been effected by this problem and to top it all off I am just past warranty. I would much rather try and fix this problem then to try and fork over another 350 for a hu.


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## chad

solacedagony said:


> *As per a yellow paper saying "Warning" on it:*
> 
> _"Always remove a connector from the (-) battery terminal before beginning any connection or installing work.
> ...
> When installing this unit, always connect he ground wire first. Ensure that the ground wire is properly connected to metal parts of the car's body. (Fig.3)
> ...
> When connecting the power amp (sold separately) to this unit ensure that the ground wire for the power amp is properly connected to metal parts of the car's body. Connect the ground wire of the power amp with a different screw from the one you used to connect the ground wire for this unit or any other device. Should the screw for the power amp's ground wire loosen or fall out, it may result in this unit emitting [magic] smoke or malfunctioning. (Fig.3)"_
> 
> 
> So they're saying to not use a common ground and to hook up the ground wire FIRST. What about if your ground wire is on a harness? Constant, memory and ground will all be connected simultaneously.



That, and if it's TRULY an issue of charged caps... and the caps are doing their job.... with no bleeder resistors.... we are still shot.


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## 60ndown

dalinkwent said:


> So is there any write-up or anything of that nature that shows how to fix this problem? I only ask because unfortunetly I am one of the many that has been effected by this problem and to top it all off I am just past warranty. I would much rather try and fix this problem then to try and fork over another 350 for a hu.


i paid $145 locally to have my noise fixed 

if your good with a soldering gun and electronics i guess you might be able to do it yourself for $4?

im not that good with it tho.


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## solacedagony

chad said:


> That, and if it's TRULY an issue of charged caps... and the caps are doing their job.... with no bleeder resistors.... we are still shot.


So you're pretty much trying your luck every time you hook this thing up?


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## chad

solacedagony said:


> So you're pretty much trying your luck every time you hook this thing up?


If I say yes would I be a hater?  

Without seeing the guts or a schematic I can not give a definate answer so I will remain quiet  

Chad


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## solacedagony

chad said:


> If I say yes would I be a hater?
> 
> Without seeing the guts or a schematic I can not give a definate answer so I will remain quiet
> 
> Chad


If it's easily tear-apart-able I'll get some gut pics for you. If not, we'll be in the dark forever 

So the problem is with these capacitors in the pre-outs? Should you discharge them every time you unhook the unit or what?


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## 60ndown

solacedagony said:


> If it's easily tear-apart-able I'll get some gut pics for you. If not, we'll be in the dark forever
> 
> So the problem is with these capacitors in the pre-outs? Should you discharge them every time you unhook the unit or what?


880,

http://i11.tinypic.com/2gwukom.jpg


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## chad

solacedagony said:


> If it's easily tear-apart-able I'll get some gut pics for you. If not, we'll be in the dark forever
> 
> So the problem is with these capacitors in the pre-outs? Should you discharge them every time you unhook the unit or what?


God only knows..... I believe the majority of the issues WE ae having are with blown pico fuses protecting the shield I imagine. I'm wondering if they are not coming up in charge with nothing attached then when attached or coming in contact with ground blowing the pico fuse. 

Is the shield on a *working* 880 ground? or floating?

Chad


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## 60ndown

http://www.elitecaraudio.com/forums/showthread.php?threadid=137088


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## solacedagony

chad said:


> Is the shield on a *working* 880 ground? or floating?
> 
> Chad


How can I tell? Is there a way I can measure continuity to find out?


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## effenay

cam2Xrunner said:


> For those who have ever had noise issues with their 880PRS or other deck, this post might help.


Great thread Cam! Thanks for the info.

Who is the source of the original quote in the first post?

Link available?


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## Mat Dope

if anyone has any DIY repair info for these HUs it would be nice. my 860 has bad noise now, and the wire around the rca ground doesnt help any more.


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## chad

solacedagony said:


> How can I tell? Is there a way I can measure continuity to find out?


If the shield of the RCA connector measures close to 0 ohms in respect to chassis ground/harness ground. If it measures low then starts climbing to infinity then it's cap coupled. If it measures say 200 ohm then it's isolated by a 200 ohm resistor.

These could be the Pico Fuses: (red circle near the top, tough to see around that cable)










Now... Does that big blue cap DC isolate the ground?

Chad


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## solacedagony

Will I have to have it plugged in to check that? Or can I do it without it being plugged in?

And none of that probing will result in a blown pico fuse, right?


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## chad

solacedagony said:


> Will I have to have it plugged in to check that? Or can I do it without it being plugged in?
> 
> And none of that probing will result in a blown pico fuse, right?


Do it completely disconnected. Modern meters have a VERY high impedance for checking resistance, it will be fine.


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## solacedagony

Between the sleeve and the chassis of the HU, I'm getting ~0.3 ohms.


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## chad

solacedagony said:


> Between the sleeve and the chassis of the HU, I'm getting ~0.3 ohms.


Well, She's grounded Too bad it's not in peices or I'd have you check the Pico fuses to see where they go 


*DON'T TAKE IT APART!* I don't want to be responsible for that one


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## solacedagony

chad said:


> *DON'T TAKE IT APART!* I don't want to be responsible for that one


The casing seems simple to get off, but it's not playing nice, so I won't push my luck.


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## dalinkwent

> Well, She's grounded Too bad it's not in peices or I'd have you check the Pico fuses to see where they go


well since my pioneer is no longer under warranty I will be looking to take her apart. If i remember correctly my rca's seemed grounded as well. So my question is, what should I look for now?


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## chad

See where I circled in the pic I posted? measure those of they look like fuses. They should not be open if in fact they are the fuses. they will lok like the little fuses tha come with christmas tre lights... only with leads to solder into the board.

And take some good Macro pics 

Chad


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## dalinkwent

Well, I just had a talk with my father, who has about 50 years of experience behind him working on airplanes and such, and he says if I can get the schematics for the board or the service manual, that he could fix this. So after looking for a while, the closest service manual I could get was that of a DEH-P8400MP. I am fully prepared to share my findings once completed, but the only thing in my way is that. So do you guys think that the 8400 and the 860 used the same board/schematics? Or better yet, would any of you happen to have a service manual for a 860mp. Either way this will get done in the coming up weeks (whenever we have the free time that is).


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## Nathan P

DEH-P8400MP would be the same schematic as the DEH-P840MP.


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## cam2Xrunner

effenay said:


> Great thread Cam! Thanks for the info.
> 
> Who is the source of the original quote in the first post?
> 
> Link available?


My good friend Dave! 

I asked him if he could answer a few of the recent questions in this thread, I'll let you know what he has to say.


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## tard

my memory is prone to be off at times, but i think i remember being told by pioneer that it's a floating ground on the preamp section.

the most common i've seen is the micro fuse, standard is 1/2 amp. any unit i've had to get repaired i've had it upped to 2 amp and no more probs.


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## solacedagony

dalinkwent said:


> Well, I just had a talk with my father, who has about 50 years of experience behind him working on airplanes and such, and he says if I can get the schematics for the board or the service manual, that he could fix this. So after looking for a while, the closest service manual I could get was that of a DEH-P8400MP. I am fully prepared to share my findings once completed, but the only thing in my way is that. So do you guys think that the 8400 and the 860 used the same board/schematics? Or better yet, would any of you happen to have a service manual for a 860mp. Either way this will get done in the coming up weeks (whenever we have the free time that is).


http://parts.pioneerelectronics.com/part.asp?productNum=CRT3650
Get to work!


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## chad

dalinkwent said:


> So do you guys think that the 8400 and the 860 used the same board/schematics? \



I highly doubt it. Are the 840/8400's having issues too?


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## chad

tard said:


> my memory is prone to be off at times, but i think i remember being told by pioneer that it's a floating ground on the preamp section.
> 
> the most common i've seen is the micro fuse, standard is 1/2 amp. any unit i've had to get repaired i've had it upped to 2 amp and no more probs.


It looks as if it's "floated" but that big ass lyitc but the flash in the pic floating around washes out the traces. But then another member metered it as a direct connectiont o ground


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## chad

solacedagony said:


> http://parts.pioneerelectronics.com/part.asp?productNum=CRT3650
> Get to work!


Holy ****! Pioneer sure am proud u dem manuals! I got the whole 2005 alpine line up for around 20 bucks I think, from Pac Parts!

Which, who, incedentally, were uber cool because I wanted the manual for the 9855 and they sent me everything BUT the 9855, they got me the 9855 manual quickly with a smile on their faces! Good cust service there!


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## dalinkwent

solacedagony said:


> http://parts.pioneerelectronics.com/part.asp?productNum=CRT3650
> Get to work!


As bad as I wanna do this, there is no way I would pay that much money. For that I would just buy a new radio. Well I guess imma have to go in somewhat blind (except for the pic that Chad posted). Oh well, it will just make it more fun that way.


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## solacedagony

dalinkwent said:


> As bad as I wanna do this, there is no way I would pay that much money. For that I would just buy a new radio. Well I guess imma have to go in somewhat blind (except for the pic that Chad posted). Oh well, it will just make it more fun that way.


Yea, you're just about half way there for 150$.


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## geaugafletcher

Well, how many of us are there that want to have better answers? We could easily chip in together and not spend much per head. We'll post the schematic for Chad and other propeller-heads to analyze and VOILA!

The question then is, "Who owns the manual?"

Maybe the better question is, "Who makes five or six photocopies of the entire manual?"


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## dalinkwent

well I did some looking and I found it for $5 instead of that crazy $144. So like I said, I would share my findings. Without further ado..... http://www.mediafire.com/?cjmwxzmnx4j (don't worry you don't have to pay).....


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## chad

I'm on that first thing tomorrow morning! The curosity is killing me!

dialup prevents me from doing it now


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## LiquidClen

tag


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## geaugafletcher

dalinkwent, you're a champ. Three gold stars for the day.


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## shewing69

If I read the plans correctly, both the 8600mp and 860mp are mostly the same, except for the little resistors (r618,r619,r621 and r626) on the board that goes to the "Model 1 and model 2" pins on the PD5928A chip. That and the DSP switch on the DSPMOD pin on the system controller chip. Do you think a 8600 could be modded into a 860mp?


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## dalinkwent

Well its done. So me and my father opened it up, which isn't hard at all, as long as you follow the disassembly guide. So we tested the pico fuse and got nothing on the meter. So we knew it had to be changed. We didn't have one handy so my father said that a 1 ohm resister would do the trick. So we soldered it in and what do you know, no more preout noise. Here are some pics... 


















... Good luck to the rest of you


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## chad

dalinkwent said:


> We didn't have one handy so my father said that a 1 ohm resister would do the trick. So we soldered it in and what do you know, no more preout noise. Here are some pics...


That's probably what they shoulda put in there in the first place! that's what most use. pico's go fast!


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## LiquidClen

So basically we need to change out the pico fuse with a 1 ohm fuse?


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## 60ndown

your dad must have a really small one


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## dalinkwent

lukeboa said:


> your dad must have a really small one


huh? If by that you mean a small 1ohm fuse, then yes.(I hope thats what your talking about)


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## LiquidClen

If I mail my 880 to you, will you fix it for me?


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## solacedagony

LiquidClen said:


> So basically we need to change out the pico fuse with a 1 ohm fuse?


That's just a resistor, not a fuse. It goes in PLACE OF the fuse.


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## LiquidClen

solacedagony said:


> That's just a resistor, not a fuse. It goes in PLACE OF the fuse.


that's what I meant. Typo. :blush:


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## chad

But 0 and 1 ohm resistors work great as fuses (Slo Blo), it's VERY common in tons of gear for protecting... from... get this.... GROUND OOPSIES! The only thing I would do different is to use a FlameProof resistor incase there's a BIG oopsie. This will keep the resistor from "flaming on" and getting that **** smoke all over the laser assembly and other components.


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## 60ndown

dalinkwent said:


> huh? If by that you mean a small 1ohm fuse, then yes.(I hope thats what your talking about)


soldering iron silly, and a steady hand  

i paid $145 to get my noise fixed, if you posted in car audio forums i bet theres 50 units at least you and you da can fix?

50 x $135 =


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## chad

It appears that the fuse is a 3A Pico, bypassed with a cap, whatever is going on to blow a 3A fuse is beyond me but I have seen some pretty high currents at low voltages in grounding situations. And again, pico's blow fast!

I'll say again that the resistor is a good idea, in fact I like the idea over the fuse but I HAVE TO SAY THIS to cover my ass, see the triangle in the schematic with the exclamation point in it right next to the fuse? Heed warning!

Juss wonderin' Do you guys also get loud pops and thumps when switching sources or muting after the fuse fails?

Chad


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## MidnightCE

dont they cover it under warranty?


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## Mat Dope

i really want to do that to my 860 that just crapped out on me. what is the number next to the pico, and can i just solder in a 1ohm ohm resister from like radioshack. also someone mentioned flame proof resistor is that what i should try and get. one last thing do you need to use any specific solder?


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## chad

Mat Dope said:


> i really want to do that to my 860 that just crapped out on me. what is the number next to the pico, and can i just solder in a 1ohm ohm resister from like radioshack. also someone mentioned flame proof resistor is that what i should try and get. one last thing do you need to use any specific solder?


FU351 in the schematic..... Should be in parallel with C354.....

I'm checking mouser in a few minutes for 1 ohm FP's, I need to order parts for an Crest amp I smoked a while back.

Chad


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## Mat Dope

the pico fuse is labled P right, and i just solder over the connections i dont need to remove it or anything? also chad what wattage resistor do i need? radio shack says they have 1/4watt 2watt and 10watt. and also is FP really nessesary?


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## dalinkwent

yes the pico fuse is labeled p. You're gonna have to look very close cause that thing is tiny. Just use my pics as somewhat of a guide (thats if you haven't downloaded the schematics that I posted earlier). As for type of solder goes, just use what you got. Its not gonna make a difference. I think it would be easier to solder the new one in if you remove the old, but its really up to you. Although when you see how much room, or lack there of, you have to work with then you will probably want to remove it. As for what type of resister, well I used a 1ohm one because we had some handy, but you can use anything lower.


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## Mat Dope

but what wattage resistor should i use? i can choose from 1/4, 2, and 10 watt 1ohm resistors.


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## chad

Mat Dope said:


> but what wattage resistor should i use? i can choose from 1/4, 2, and 10 watt 1ohm resistors.


1/4 watt. I am having a hell of a time finding FP 1 ohm resistors on mouser but I just got back from lunch and trying again.

FP is not entirely necessary but I like to use them in sacrificial situations, it's a personal design requirement


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## Mat Dope

ok cool im going to go pick up the parts and try this later or tomorrow and ill let you know how it goes. and try to post pics.


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## chad

Mouser does not have any small 1 ohm FP's or 0 ohm FP's. When soldering be quick and gentile with the heat..... I prefer a 1/16" "screwdriver" tip on my weller for this stuff.


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## ryan s

any luck on finding flame-proof 1ohms, chad? i have a bunch of 1/4w resistors from RS, but none are 1ohm  i might be buying an 880 with noise to save some money and fix it myself. im not scared to take anything apart lol  correction: anything but my dSLR...that babys never coming apart


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## chad

No, did not see them at digikey either. i have to go to ECE stores tomorrow, I'll ask them, those ladies can find ANY part


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## Mat Dope

sence its just a fuse for the rca shields and stuff couldnt you just connect the two points with a little strand of wire or something. why does it need to be 1ohm?


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## dalinkwent

technically you can do that. I just don't know which of the two would be stronger?


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## ryan s

im curious to know if any other resistor values would work...

if anyone can find the resistors in question, ill take a couple for a rainy day


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## chad

A 1 ohm was used because it was available. They also make a 0 ohm resistor (one black band)

I would certainly kep it VERY low.

If there was anough room I'd say put a damn fuse holder on the back of the unit


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## solacedagony

chad said:


> If there was anough room I'd say put a damn fuse holder on the back of the unit


Couldn't you just drill two holes in the back of the casing and run the wires out and put in one of those small inline fuse holders?


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## chad

That is almost akin to whip out the "bling bling MF's" pic again. Or maybe I need to make up a "Dat's Ghetto!" Pic  

Don't see why not, you could use a standard fues, even a slo blo that could take the abuse of connection and still offer the same protection.

If it's done this way I will need a pic for the "Dat's Ghetto!" pic canadate


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## Mat Dope

if its for the ground why do you even fuse?


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## chad

Mat Dope said:


> if its for the ground why do you even fuse?


It's to keep the unit from burning up the ground traces if the amp tries to derive ground thru the head (like a broken ground connection or a dazed troubleshooter)..


Chad


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## Mat Dope

oh ok, so as long as you dont hook stuff up wrong, pay attention and whatnot you dont NEED to use a resitor or anything. because i cant find any 1ohm around town either so i think ill just use a little wire and be careful


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## chad

Mat Dope said:


> oh ok, so as long as you dont hook stuff up wrong, pay attention and whatnot you dont NEED to use a resitor or anything. because i cant find any 1ohm around town either so i think ill just use a little wire and be careful


You need a link weaker than the trace on the PCB  Most units use a resistor anyway.. and there's never an issue unless someone screws up. Many feel, as I do, that the pico fuse is overly sensitive. If you are damn careful you can do as others have done with the "wire wrapping modification"


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## Mat Dope

i tried doing that with the RCAs and it didnt work. i just took 1 strand of copper wire out of a piece of wire i had laying around and soldered it accross the pico, i just put the unit in and it works great. no noise at all. i was going to get a new HU if i couldnt get this fixed so ill just get a new one if it breaks but hopefully it wont. anyway its working great right now. if i find a 1ohm 1/4watt resistor ill put it in though. untill then i just have to be careful.


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## dalinkwent

well i might be able two spare some resistors if you guys really need them. Just pay for whatever type of shipping u want and I will be happy to helpout fellow diy'ers.


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## Mat Dope

if you have a 1ohm 1/4watt fireproof i would like one


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## ryan s

a fuse holder through the back of the case may be ghetto, but its on the back, inside the dash. sssssh, no one needs to know 

i would be tempted to use the ATM style (the itty bitty ATCs) since I carry a crapton with me in the car. (never needed one, but better safe than screwed).

if anyone does have an extra resistor or two, id pay for em cause i dont have the time to hunt em down...


----------



## tanakasan

Hi all, registered to make my first post here. A frequent visitor, tons of knowledge and advice available here!

Did the Pico fuse "fix" today. Thanks to all of you who have contributed their time and knowledge in this thread for the rest of us!

I did take some pics of that little bugger (FU351 in the upper right corner near the brass standoff) since there were no closeups specific to the PRS880. I forgot to shoot the finished repair in my excitement. [email protected]

Just tinned the ends of the Pico fuse and jumpered across the legs with the 1ohm 1/4watt resistor. A couple pieces of teflon spaghetti tubing added for insulation on the legs of the resistor. I also added an external case ground wire. Hope to never open this unit up again.

Its easy, next one probably can be done in 1/2 hour!


----------



## solacedagony

ken tanaka said:


> Hi all, registered to make my first post here. A frequent visitor, tons of knowledge and advice available here!
> 
> Did the Pico fuse "fix" today. Thanks to all of you who have contributed their time and knowledge in this thread for the rest of us!
> 
> I did take some pics of that little bugger (FU351 in the upper right corner near the brass standoff) since there were no closeups specific to the PRS880. I forgot to shoot the finished repair in my excitement. [email protected]
> 
> Just tinned the ends of the Pico fuse and jumpered across the legs with the 1ohm 1/4watt resistor. A couple pieces of teflon spaghetti tubing added for insulation on the legs of the resistor. I also added an external case ground wire. Hope to never open this unit up again.
> 
> Its easy, next one probably can be done in 1/2 hour!


Did you get it back into your dash? Did that fix resolve all your noise issues?

Thanks for posting!


----------



## tanakasan

Yes...and yes!

Back into dash is a piece of cake. The fix was not difficult and completely eliminated the noise issue I had.

The iPod was dead quiet but the CD was noisy when paused and volume up. I could also hear background noise and the mech "rumbling" though the speakers while changing tracks. This was with the "grounding the RCAs" band-aid which removes 90~95% of the noise.

This time it took around 2 hours b/c there were no service manuals for PRS880 and no pics of the offending component. I removed some items that did not need to come out. Next one  can be done in 1/2 hour.

Hope my pics helps someone else down the road...and thanks again to all the previous posters!


----------



## audiorailroad

this problem kept me from buyin one. until now. such an easy fix. thanx for the info and research guys.


----------



## geaugafletcher

Thanks for the follow-up. Did you remove the board to get better access to the fuse? I can't imagine getting a soldering iron down in there...


----------



## illnastyimpreza

so basicly you have to be a meathead to blow one of these...which most of are or have been 

Personaly I have blown up quite my share of headunits/amps/speakers etc etc by messing with them "hot"

as I general rule of thumb, I NEVER...I repeat NEVER make any connections while there is any power in the system anymore....unless it cannot be avoided.

follow that simple rule, and your chances of blowing anyting up are greatly reduced 


BUT...good thing there IS a fix for this ! many thanks to those who took the time to figure it out ! I'm really hoping I never blow that ****er !


----------



## tanakasan

illnastyimpreza said:


> so basicly you have to be a meathead to blow one of these...which most of are or have been


Well, I could be a meathead  but these guys pop if you just look at them funny!

Did not hot swap RCAs, just relocated ground to try and eliminate very minor alt whine on tweet amp. Yes, amp +12v disconnected @ battery, power harness disconnected at back of HU. Turned key and got the most gawd awful thumps and pops from the system. Immediately turned off, but the deal was done. Did the RCA band aid but wanted to finally solve this puzzle.

Did not know about adding an external case ground to Pioneers. Always had Sony/Clarion/Eclipse w/o any issues. Been tinkering in car audio since the early 80s. Monolithic EQ/x-overs, Monolithic, Carver, PPI and Soundstream amps and Sony AM/FM/CD dead head with Vifa, Dyn drivers. Have not blown any speakers or amps or HU yet, <knocks on wood> this one is as close as I have come.

geaugafletcher, I did remove the front panel/main board from the case (to see the pico fuse connection underneath) but it did not help!


----------



## chad

ken tanaka said:


> Well, I could be a meathead  but these guys pop if you just look at them funny!!


Seems you are right IMHO and you are NOT a meathead



ken tanaka said:


> Did not hot swap RCAs, just relocated ground to try and eliminate very minor alt whine on tweet amp. Yes, amp +12v disconnected @ battery, power harness disconnected at back of HU. Turned key and got the most gawd awful thumps and pops from the system. Immediately turned off, but the deal was done. Did the RCA band aid but wanted to finally solve this puzzle.


Yep



ken tanaka said:


> Did not know about adding an external case ground to Pioneers. Always had Sony/Clarion/Eclipse w/o any issues.................................. but it did not help!


Because there should NOT be a fuse there, it's ****ty, People know my stance, I think it's wrong.

Chad


----------



## envisionelec

chad said:


> Seems you are right IMHO and you are NOT a meathead
> Yep
> Because there should NOT be a fuse there, it's ****ty, People know my stance, I think it's wrong.
> 
> Chad


I'm officially out of car audio repair now, but I find this thread particularly interesting. Pioneer has a long history of "crap for brains" line output irregularities. The pico fuse has been the technician's best kept secret for a number of years. Before that, it was the muting transistors and vaporized traces. It was a 10 minute fix I could do in my sleep and charged $43. $145 seems awfully steep given that Pioneer's CD players are so easy to disassemble and troubleshoot.

The most interesting thing is that Pioneer is aware of the problem and could easily fix it. Stop using 5 mil ground traces on your boards, Pioneer! See, Pioneer wants you to fix your problem so they punish you by causing damage to the radio. As a PCB layout guy, I understand the fixes to this: Ground the RCA cables to a location near a chassis screw. 

I understand their stance - they are trying to minimize noise induction by grounding the RCAs to the source - namely the output OPAmps. But everyone (sic) knows that an OPAmp can only source a few mA and it makes no sense to try and force the signal to seek out the REAL source given that the overriding Ground is the Chassis - not the audio signal - in a headunit.

It's just another case of narcissistic engineering.


----------



## chad

ezaudio said:


> I'm officially out of car audio repair now,


And you sanity is slowly regaining?   It's a nutty world of repair I found out.

Most units, amps and all, I have seen just use a resistor as opposed to a fuse that is trigger happy. A 0 or 1 ohm resistor takes the heat for a bit before it looses it's cookies. And when it does loose it's cookies you have done something WRONG but still protects the unit. Also when it looses it there is a stench, to remind the person who did something WRONG that something is amuck and they should cease while they are partially ahead.

Chad


----------



## illnastyimpreza

ken tanaka said:


> Hi all, registered to make my first post here. A frequent visitor, tons of knowledge and advice available here!
> 
> Did the Pico fuse "fix" today. Thanks to all of you who have contributed their time and knowledge in this thread for the rest of us!
> 
> I did take some pics of that little bugger (FU351 in the upper right corner near the brass standoff) since there were no closeups specific to the PRS880. I forgot to shoot the finished repair in my excitement. [email protected]
> 
> Just tinned the ends of the Pico fuse and jumpered across the legs with the 1ohm 1/4watt resistor. A couple pieces of teflon spaghetti tubing added for insulation on the legs of the resistor. I also added an external case ground wire. Hope to never open this unit up again.
> 
> Its easy, next one probably can be done in 1/2 hour!


ok so where is the pico fuse ??


----------



## geaugafletcher

> FU351 in the upper right corner near the brass standoff


Check your quoted text, bud.


----------



## illnastyimpreza

geaugafletcher said:


> Check your quoted text, bud.


ahh... semi retard moment there... thanks


----------



## paulpassat

Trying to fix pico fuse. Does the cd assembly need to be removed.thanks


----------



## blacklabel

on the 880s PCB, what are the little pieces that are labelled "473, and 222?" i tried to fix my 880 and knocked the a 2 little pieces labelled 473 and 222. i went to radio shack and found nothing. i dont even know what they are called and don't know where to look for these.


----------



## tanakasan

paulpassat said:


> Trying to fix pico fuse. Does the cd assembly need to be removed.thanks


No, it does not for an 880. I removed mine the first time, but it does not help. Its just an uber tight squeeze to solder in the available space. I did mine out in direct sunlight with magnification. GL!


----------



## ehduque7

Hey Everyone. Been reading around trying to figure out what is wrong with my install. 

My Pioneer DEH 7900BT has been making a loud static noises and picking up alot of noise from my car. For example, if I turn my air conditioner on, I get a loud whining noise. But if the AC is off, I just get a static noise. If I unplug the RCA's from my amp, I don't get the noise anymore.

I thought it was my headunit and that it had the blown fuse everyone is talking about so I took it into the Pioneer repair shop. I just got a call today from them telling me that my headunit is fine and nothing seems to be broken. 

If the fuse is blown, will the noise be un-bearable? As in, you will hear it over the music if the music is turned up pretty loud? 

THanks for your help.

-Edward


----------



## kyheng

Just got Pioneer deck repaired few days ago. As no more warranty ofr it, I sent to a local audio repair store. Takes me 1 week for the repair. A resistor was burnt due to short-circiut. So he changed the resistor and redesign the circuit as normal Pioneer design its earthing circuit can easily get burnt.


----------



## onecoolee

Maybe you guys can give me a little advice... I have a complicated Pioneer system in a show car (Nissan 350Z). I have always done my own work, and noise issues are my nemessis !

Anyways, I decided to upgrade my existing DEH-p840mp Premier head unit this week, and swap it out for the newer flashier, multicolor OEL display w/bluetooth telephone options DEH-P980BT. I have 2 Phoenix Gold ZX amps, a power bridge, Audio Control EQX2, ESP3, and other equipment too, which is not related to this problem.

Anyways, after I rewired the head unit, I had problems with the unit seeing my devices on the IP-bus, which are a 12 disc Premier changer (CDX-1279), IPod adapter (IB100II), TV tuner(GEX-P7000)-linked to the factory NAV, and Sirius Radio module (SIR-PNR2). All of these same devices were hooked up to the 840 head without any noise issues. SO, I removed the passenger seat to get at the above mentioned devices... I found that my main IPbus cable had gotten strained a little during the install and apparently started to fail... so in the process of pulling a new IP bus cable, with the power on, and doing some hot-swapping of RCAs to compelte the rewiring, I now have noise... LOADS of it with the head connected to my high quality RCAs. This was not there before, and I don't recall any noise when I first powered up the unit and tested the CD SRC in the head initially. I hear pops, clicks, humm, and some alt whine that was not there before. I know the noise is not being radiated, and I am using good quality twisted pair RCAs to minimize any radiated noise effects, as my 03 350Z is a noisy environemnt.

Before today, I was unaware of these so called pico fuses.

I bought my head unit online, and it sounds like there's a good chance I cooked these puppies now. There is still warranty left on the unit, but I bought it online, so that makes the repair complicated. SHould I find these inside and replace them myself with a resistor ? Does everyone think this is my problem, and does anyone know if the 9800/980 designs use picofuses in the output phase of the rca circuitry ? I put my old HU back in just as a test to see if it was noisy, but I hotswapped it as well, so I probably f'd it up in the process, and I have nothing else left to try now. Dumb mistake, and I never have had any problems like this before... but I have never done a system with 10 pounds of **** in a 5 pound bag either !

Any advice is appreciated... and if anyone knows if these fuses will be replaced under warranty, I would love to know that as well... I hate waiting for repairs and being head unitless... but I also hate to void my warranty on a $500 head unit.


----------



## kyheng

I would say try to get an audio repairer on your place... Atleast he will check it better than you. Sometimes is good to let the pro to do the job. As far as I know, warranty won't cover online buying(not installed by Pioneer authorized installer). You can also send it back to Pioneer service center but for sure I know that the noise problem will be back again if you are doing hot swapping RCAs again.


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## onecoolee

Like my thread stated...I don't make a habit out of hot swapping RCAs or making changes with the wiring of any car audio equipment with the power on or ground cable connected at the battery... this just happened to occur when I was tryign to debug the ip-bus cabling which I found was bad, and in the process of debugging that issue, it looks like I may have created an even bigger problem. In all my years of installing and doing this type of work (10 years growing up and for another 15 years since then off an on), I have never seen this problem occur. I always button up my install before I turn anything back on or reattach the ground... this was an unusual situation in that it was hard to find the bad cable wihtout having access to the back of the head unit... therefore, I couldn't permanently mount the HU. I don't think I did anything out of the ordinary, and I never would have thought that plugging in a different source, or hot swapping RCAs would kill my head unit, even if it was properly grounded...

Being an engineer myself, this sounds to me like a poor design, and a scam for Pioneer to make money on repairs, like a post earlier in this thread states.


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## kyheng

Yes, you are right, the circuit design for most(can I use all?) on RCA earthing are very bad, can easily get burn.


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## onecoolee

well, as this thread predicted... my excess noise with my new Pioneer 980BT head unit was a reuslt of the picofuse failure problem. I removed my new 980BT head unit last unit, and took it apart. I found 1 picofuse which connected the grounds of the rcas directly to ground, that fuse was open circuited. Without the fuse there, the ground is cap-coupled like this thread states.

I didn't replace the picofuse part, but I did install a jumper across the open circuited picofuse re-establishing the connection to ground for the RCAs. I didn't take any pics b/c my digital camera doesn't do macro pics very well, but the only fuse I found was located just to the left of the RCA lead conenctor inside the unit. It was fairly easy to find and the unit was suprisingly easy to disassemble.

Anyways, it seems like the 980BT is more suseptible to noise, b/c I do still have a slight bit of noise compared to no noise at all with my 840mp, but the overall noise is a lot better than it was with the pico blown. I will work on the noise issue later today and hopefully track that down...

Thanks for a quality forum and for some great posters and, most of all, alot of credible information !


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## kornsined

Nice! I can fix my 8600mp now. I know I was screwing around with hot RCA's before this happened, definitely the cause. Yes I am a meathead too.


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## tcguy85

i did the pico fuse bypass on my 880 back when i was having noise issues. turned out not to be the problem but now it's done anyway.


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## chad

You could prevent it by not buying a pioneer


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## tcguy85

chad said:


> You could prevent it by not buying a pioneer


but pioneer is the best!!!!


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## chad

I question a company that "protects" it's output section with under-rated lightning fast fusing.


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## kyheng

Advantages of having a fuse on RCA pre-outs : it will prevent damage to amp. I get someone modified my P9650's RCA pre-out, it won't blow when doing hot-swapping, but it blow my amp's RCA earth. So still no hot-swapping on Pioneer HUs....


----------



## tcguy85

chad said:


> I question a company that "protects" it's output section with under-rated lightning fast fusing.


yea i don't understand it either. but many people, me included, love their higher end pioneer units.


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## chad

kyheng said:


> Advantages of having a fuse on RCA pre-outs : it will prevent damage to amp. I get someone modified my P9650's RCA pre-out, it won't blow when doing hot-swapping, but it blow my amp's RCA earth. So still no hot-swapping on Pioneer HUs....


WHAT?

Recording studios all over the world have what's called PATCHBAYS, intended for patching and normalling guzintas and cumzatas on ALL the equipment in the room. Do you REALLY think when patching for a session we throw the main breaker? 

Hell no!

I have only repaired ONE device that failed (repeatedly) from hot-patching and it was a botched install that used TRS for mic inputs and the morons were leaving the phantom power on, with a console that protects the oputputs with a 22V zener to GROUND (duh) most rail clamping would even take that with ease


----------



## kyheng

Chad : As far as I know, P880 has a pico fuse on it, while others has the resistor. What my man done is modified the circuit(changing to higher rating resistor I guess). It still will blow, but not like the original circuit, just a slight short also can blow it.


----------



## chad

kyheng said:


> Chad : As far as I know, P880 has a pico fuse on it, while others has the resistor. What my man done is modified the circuit(changing to higher rating resistor I guess). It still will blow, but not like the original circuit, just a slight short also can blow it.


That's the thing to do IMHO, go back to the old way of doing things


----------



## W O T

Can anyone help me do this? My pioneer 860 mp just started making those wierd noises and I have it troubleshooted to the rca outputs, so im assuming its this

I have the cd player in my hands, but dont know how to take it apart (dont want to try unless I get a bit of advice) if youre looking at it from the top, all I see is 2 black screws on the middle left and middle back. 

Will I also be looking for the FU351 circuit and just solder some wire across it (no electronics stores in town)

Im new to soldering and definetely dont knoww ehre to look in my deck so I need some help

let me know please, I'll pay for a good diagram and walkthrough


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## azngotskills

No offense intended, but with your post above i would take to a professional. Im sure your capable of doing it given the proper tools and information but i wouldnt risk messing something up more severe. Just bite the bullet and pay for the service to do it properly. Again i mean no offense by this post


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## pikers

Lightninghoof said:


> This is somewhat unrelated, but I've had too many Pioneer/Premier HU's fail over the past 15 years to give them any more of my money. From faceplate backlights failing, to whine/ground issues that pop up out of nowhere, to CD read errors, etc. Just feels like disposable car audio to me.


Had an Alpine 7969 do the exact thing that Pioneers are notorious for (hotswapping ground noise appearing), so they aren't (weren't ) alone.

Looks like the "turn power off prior to making any connections" thing is true. Now if it happens unplugged, that's pure crapola.


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## illnastyimpreza

is a blown pico fuse easy to tell(hear) ???

I can't remember if I swapped RCAs with the volume on low...

would this likely cause it to blow ??


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## kyheng

Hotswapping a Pioneer Hu's RCA = chances to get the fuse blow as high as 95%....


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## tcguy85

i don't understand why people would plug in or unplug rca's with the HU or amp or anything on in the first place. why would you even have the keys in the ignition while installing or uninstalling or whatever? it's SUCH a simple problem to avoid.


----------



## illnastyimpreza

tcguy85 said:


> i don't understand why people would plug in or unplug rca's with the HU or amp or anything on in the first place. why would you even have the keys in the ignition while installing or uninstalling or whatever? it's SUCH a simple problem to avoid.


might be a simple problem... But one would think something as simple as unplugging + plugging in RCA connections wouldn't freakin blow up your headunit ..l. 


I usualy make every other connection with power off...

but RCAs are plug and play... which is why many people mess around with them with the power on the music running....


----------



## W O T

W O T said:


> Can anyone help me do this? My pioneer 860 mp just started making those wierd noises and I have it troubleshooted to the rca outputs, so im assuming its this
> 
> I have the cd player in my hands, but dont know how to take it apart (dont want to try unless I get a bit of advice) if youre looking at it from the top, all I see is 2 black screws on the middle left and middle back.
> 
> Will I also be looking for the FU351 circuit and just solder some wire across it (no electronics stores in town)
> 
> Im new to soldering and definetely dont knoww ehre to look in my deck so I need some help
> 
> let me know please, I'll pay for a good diagram and walkthrough


I need help with this, I popped off the back cover by prying it off gently. now I came to the part where I pop off the 4 screw that the picture on page 8-9 said to do, now Im stuck, what comes out next, i need to get to this mother board, bought a nice new solderring gun


----------



## azngotskills

W O T said:


> I need help with this, I popped off the back cover by prying it off gently. now I came to the part where I pop off the 4 screw that the picture on page 8-9 said to do, now Im stuck, what comes out next, i need to get to this mother board, bought a nice new solderring gun


I did give you some advice here but if your going to go ahead and do it, i wish you luck. Please post the outcome


----------



## W O T

I read your advice, I fix things myself, especially with specialized people willing to lend a few pointers that will let me save my money and spend it on useful things.

I just need to know how to get it apart, I got the back cover off, then the 4 screws, now I need some guidance.

thanks


----------



## pikers

tcguy85 said:


> i don't understand why people would plug in or unplug rca's with the HU or amp or anything on in the first place. why would you even have the keys in the ignition while installing or uninstalling or whatever? it's SUCH a simple problem to avoid.


Yep, but it really shouldn't regardless. Think about how often this happens in home audio--never. The fact that it occurs in any car product is the type of thing that prevents this from being taken as seriously as it could.


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## W O T

Nevermind, Im looking at it right now, there are 4 perimetere screws on the top, below them is the screws that are supposed to come out. I think I may be onto something lol


----------



## illnastyimpreza

pikers said:


> Yep, but it really shouldn't regardless. Think about how often this happens in home audio--never. The fact that it occurs in any car product is the type of thing that prevents this from being taken as seriously as it could.


you got that right...

Its insane to me sometimes the differences between the 2...


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## tcguy85

pikers said:


> Yep, but it really shouldn't regardless. Think about how often this happens in home audio--never. The fact that it occurs in any car product is the type of thing that prevents this from being taken as seriously as it could.


all i know is that i never hook up, or unhook anything when it's turned on. just a safety precaution. a pretty easy one at that.


----------



## W O T

Ok so I got the unit apart, Im looking at the circuit board. How exactly do I locate this exact LITTLE piece, **** is that stuff every tiny. I dont know if my cold heat solderring gun is gonna get in that tight space, might have to use dads old stick one.

Need advice on how to locate and repair that problems spot


----------



## txbonds

Darn you guys. Now I'm scared of the pioneer head unit I preordered. Is this problem common just to pioneer, or to all head units? Is clarion known to have this problem?


----------



## southbark33

Anyone know where the fuse is located on the DEH-P5900iB model?
I took the HU apart and cannot manage to locate anything that has a label starting with FU-???
I'm searching near the area where it says "RCA", I guess I'm just not sure exactly what it looks like. I do see this rather large blue looking resistor thing that seems to be unmarked, but most people explain how hard it is to find, and this thing is massive... it can't be it. If anyone has a picture of this particular model, I would be very grateful. I'll post a pic of the circuitboard in a little while...


----------



## seddon

well my D1 has this problem the pico fuse went and pioneer is charging $2-300 and a 4-6 week turnaround. Can't find any shop in NYC area to fix it.


----------



## southbark33

Well, I found the pico-fuse, attempted to solder a 1ohm 1/4 watt resistor in place of it, and it didn't solve the problem. Anyone else try it for the model DEH-P5900iB ? Maybe I'm soldering it incorrectly or somthing, I have no clue... for right now I'm just working the grounded RCA workaround in the back of the HU, it works about 85%-90%, I still get really bad "rumble" from my subs if I have the volume on low, and the subs pick up the engine noise. Besides that, it's bareable. I'm a little upset that I took the time to disassemble the entire HU about 6 different times to resolder the damn resistor, and each time to no avail.

I have pics of the disassembly and the modification with the resistor in place if anyone is interested in seeing them...
If you think you may know what I have done wrong and need to see a pic, please let me know, any info is appreciated.
I really wish we could get a certified Pioneer tech on this forum who would be nice enough to help us all out...


----------



## tngisaga

I tried to repair the noise problem in my 5900ib too, but it didn't work. I tried fixing it with the resistor first, but that didn't do anything. I tried to do the jumper with a strand of copper and I think I just killed my stereo. None of the buttons work anymore and it only turns on and off. Maybe I'll check the connections in the head unit later.


----------



## southbark33

I think the grounding circitry is different in the 5900iB model, because the Pico fuse is located on the underside of the motherboard, instead of on top. Maybe there is another fuse or somthing that we are failing to find on this model...
If anyone is good at deciphering schematics, I have the 5900iB service manual on file, if anyone wants to check them out just send me a PM.


----------



## tngisaga

I solved the problem with the head unit not turning on. There was a lose metal strip on the ribbon cable of the CD player, and I just reattached that to make it work. Anyway, the use of a strain of copper wire didn't work for me. It's the same old story. It has hissing while the car is on, but it just whines when the engine is on. I thought there would be three fuses (Front, Rear, and Sub outputs), but I could only find one (FU352). I looked and looked, but couldn't find any indication of other fuses. What have you done southbark33 to try and fix it? Duuude I'm just about ready to throw this piece of crap in the trash. Haha.


----------



## BlueSQ

I had this problem...its a microfuse I can't fix it either, but its located on the far rear of the circuit board by the outputs in the middle. If you have the right tools and knowhow you can do it. Otherwise its $70 for the repair shop to deal w/ it...it was free for me cause I said i bought it from a dealer. 

The other way to do it is isolate which set of outputs is doing it, and ground the RCA's, basically close the loop on itself. Use cheap rcas youll have to ruin them to do this.

Dont toss it, the damn thing was $400 shipped its not trash, it's been a strong performer for the price - this thing has more options on it than a Maybach.


----------



## southbark33

Well, I haven't fixed the noise 100%, but the fix I have done has reduced the noise about 80-90%. All I did was ground the RCA pre-outs in the back of the HU to a screw on the HU. Go to this link to see pictures...

http://www.caraudio.com/forum/showthread.php?t=147694

All you do is wrap 16 or 18 AWG bare speaker wire around the shielding of the RCA Pre-outs. Then bolt down the loose end of the wire to a screw or bolt that is already on the HU casing. This will result in directly grounding the ground loop noise that is being fed through your RCA cables before it can reach your amps. It works, but not 100%, you may still hear a slight whine coming from your speakers if you listen to a quiet song, or while the radio station is quiet. If you do try this method, please keep me posted on how it goes. If you happen to have subs wired into your system, could you let me know if you get engine "rumbling" noise produced through the subs, I'm curious if I'm one of the only ones with that problem still.

Good Luck,
This fix will usually work 95% of the time

I'm still not satisfied with it, and will continue to strive to find a definite fix for the fuse or problem with the circuitboard. If you find anything, let me know.


----------



## seddon

^^^ That works if you don't have a blown pico fuse but alot of people have added an LOC instead of using the RCA's and have had better results. Check this link out for details
http://www.avic411.com/forum/viewtopic.php?t=13862


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## tngisaga

Yeah, i was just kidding about throwing the head unit away. It was just something said out of frustration. Anyway, I tried to fix the micro fuse that's near the RCA outputs, but that didn't work for me. I might think about taking it to a repair shop, but I might use that $70 towards getting maybe a different head unit.


----------



## jrwalte

I had horrible alt whine coming through my 880PRS due to the blown pico fuse. I planned on placing a resistor on the FU351 spot and even found a 1 ohm 1/4 watt flame proof at my local FRY's. But I couldn't believe how small this pico fuse is. I wasn't able to solder a resistor in that small space with the tools I had. 

I instead took the resistor, bent the end of the metal leg, laid it across the pico and then soldered it to join both points (I tried first snipping a small piece of the leg off but I couldn't get it to stay in place to solder it). I then snipped off as much of the excess leg as I could with a pair of nail clippers (first small thing I could find ) and folded over the excess upon itself.

I just installed the HU and all noise is gone. I don't even have a soft whine with my gains turned all the way up. I'll just have to be careful with my RCAs and know when and when not to remove them. Easy enough, since I now know.

Here's a pic of the finished look. The quality is crap, but if you zoom out you can make it out. It's directly to the right of the triangle with the ! in it which is below the screw with the blue mark in the upper left corner.

http://home.comcast.net/~jrwalte/102_1363.JPG


----------



## southbark33

jrwalte said:


> I had horrible alt whine coming through my 880PRS due to the blown pico fuse. I planned on placing a resistor on the FU351 spot and even found a 1 ohm 1/4 watt flame proof at my local FRY's. But I couldn't believe how small this pico fuse is. I wasn't able to solder a resistor in that small space with the tools I had.
> 
> I instead took the resistor, bent the end of the metal leg, laid it across the pico and then soldered it to join both points (I tried first snipping a small piece of the leg off but I couldn't get it to stay in place to solder it). I then snipped off as much of the excess leg as I could with a pair of nail clippers (first small thing I could find ) and folded over the excess upon itself.
> 
> I just installed the HU and all noise is gone. I don't even have a soft whine with my gains turned all the way up. I'll just have to be careful with my RCAs and know when and when not to remove them. Easy enough, since I now know.
> 
> Here's a pic of the finished look. The quality is crap, but if you zoom out you can make it out. It's directly to the right of the triangle with the ! in it which is below the screw with the blue mark in the upper left corner.
> 
> http://home.comcast.net/~jrwalte/102_1363.JPG


damn, why does that method only work for the older models of the Pioneer HU's? I tried the same thing with my 5900iB model (pico on the underside of the motherboard), but it doesn't do a damn thing... if anyone gets this working for a newer model, please let me know.


----------



## fliplyricist1

I didn't hotswap, but I bought my 880 used, and now notice alternator whine on my unit 

Grrrrr...has almost the full SquareTrade warranty remaining, but I'd rather fix myself if its simple.

So if I'm understand correct, all you need to do is use a single 1/4watt 1 ohm resistor such as the following:

http://www.stuffdownunder.com/elect...roducts_id=8&zenid=ad77619r1q8iktn9ckkdvieek0

and remove the existing pico fuse and solder it in its place? Also, the pico fuse looks extremely small from the pics...what kind of soldering iron are you guys using?

Thanks


----------



## txbonds

If you have a warranty, you should probably use it. Otherwise you may void any remaining warranty if you try to do it yourself.


----------



## fliplyricist1

^^ good point, hopefully turnaround time is good...


----------



## jrwalte

fliplyricist1 said:


> ^^ good point, hopefully turnaround time is good...


Except it can just pop again. I didn't remove the pico fuse. I didn't even use the resistor. I just used the metal leg of the resistor to jumper across the two ends of the pico. I used a typical 15 watt soldering iron. If you have an expensive mini soldering gun then you could probably work the resistor on. It was way too small for my equipment and i wasn't going to spend 40+ for a mini soldering gun.


----------



## fliplyricist1

jrwalte said:


> Except it can just pop again. I didn't remove the pico fuse. I didn't even use the resistor. I just used the metal leg of the resistor to jumper across the two ends of the pico. I used a typical 15 watt soldering iron. If you have an expensive mini soldering gun then you could probably work the resistor on. It was way too small for my equipment and i wasn't going to spend 40+ for a mini soldering gun.


thanks...ahh so you just kept the pico fuse there and just jumpered across it with the new resistor? or am I not understanding what 'jumpered' means...sorry for the n00bishness...


----------



## jrwalte

I didn't use the resistor, since the space was too small for me to get it soldered on. I just used a piece of metal (the resistor's leg) and soldered it across the two points of the pico fuse to 'jumper' it. A piece of exposed wire (remove the sheath) can work as well. You're just trying to connect the two points so the RCAs will have a path to be grounded.

Just keep in mind that if you don't have the resistor, you run a greater chance of blowing your head unit if you ever have a surge of power run through your RCAs, which is unlikely if you follow the precautions that have been mentioned in this thread (not hot swapping RCAs, for instance).


----------



## fliplyricist1

jrwalte said:


> I didn't use the resistor, since the space was too small for me to get it soldered on. I just used a piece of metal (the resistor's leg) and soldered it across the two points of the pico fuse to 'jumper' it. A piece of exposed wire (remove the sheath) can work as well. You're just trying to connect the two points so the RCAs will have a path to be grounded.
> 
> Just keep in mind that if you don't have the resistor, you run a greater chance of blowing your head unit if you ever have a surge of power run through your RCAs, which is unlikely if you follow the precautions that have been mentioned in this thread (not hot swapping RCAs, for instance).


ahhh ok gotcha, thanks for the info...so exactly how did you solder the legs of wire, since I imagine it's still a small confined space to work with on pieces that small, especially with how big even the smallest glob of solder is when working with normal irons...

would it be basically the same thing just putting a large glob of solder on the pico itself so that it grounds both points?


----------



## jrwalte

fliplyricist1 said:


> would it be basically the same thing just putting a large glob of solder on the pico itself so that it grounds both points?


Yup. I used the metal to help make a better connection than just solder.


----------



## fliplyricist1

jrwalte said:


> Yup. I used the metal to help make a better connection than just solder.


awesome, I'll give this a try this weekend and see how it goes

thanks again


----------



## tnynyn

is there any way to tell if the pico fuse is blown? I have a d3 btw


----------



## chad

By bridging across the fuse you loose ALL the protection it offers, I don't think that's a good idea, lessening protection so it's not trigger-happy, yes. Penny in the fuse-box, no.


----------



## tard

tnynyn said:


> is there any way to tell if the pico fuse is blown? I have a d3 btw


check continuity. should have it on both sides of the fuse and to the HU case, or touch the ground pin on the main harness plug in.

if not, solder a small piece of wire on each side of the fuse and run them external out the back of the unit. then you can wire in a fuse holder, glass or ATC, use a 1 amp. next time it goes, it's quick and easy to replace.


----------



## txbonds

tard said:


> check continuity. should have it on both sides of the fuse and to the HU case, or touch the ground pin on the main harness plug in.
> 
> if not, solder a small piece of wire on each side of the fuse and run them external out the back of the unit. then you can wire in a fuse holder, glass or ATC, use a 1 amp. next time it goes, it's quick and easy to replace.


Unless I missed it somewhere in teh first 16 pages, this is the best idea I've read on this thread yet. How simple it should be to just relocate this fuse to remote location outside the unit for a normal fuse. Wouldn't do it to a unit without problems, but on one with problems, it might be the key.


----------



## tard

i didn't catch anything like this in earlier pages. only the initial write up talking about things completely different than the micro fuse problem.

i was thinking about telling pioneer to do this with a replacable fuse in the back of the unit (like the main fuse is), but i ended up thinking they wouldn't do it. in the event someone put too large of a value fuse in there, it wouldn't blow in time to save the preamp section. so i figured they wouldn't want to take that risk.

but you're right, no need to do this mod unless the micro fuse is already blown.


----------



## yunvme666

good read guys, im glad i found this forum , make a few bucks off local people hopefully....lol... i never thaught about fixing mine i just replaced them....lol... but i got a prs880 now and its good to know theres a easier fix then sending it off if anything goes wrong... thanks guys....


----------



## JonMR2turbo

Hey guys, I am having a problem with my 800prs. I think it's the pico but I want to make sure because I haven't really seen anyone describe the noise I am getting. 

Here is a video of it: http://www.youtube.com/watch?v=LeHmM_anre4 

Keep your computer volume low. This noise is very loud and does not change with the volume knob. Most of the time I get it but sometimes it will go away and I'll just be left with really bad alt whine. This happened once before and then I had the unit replaced. Then it happened again after not even a couple hours of playtime. The noises you hear in the video came on suddenly and the strange part is that both times it did it when I pushed my clutch pedal in. My install is fine and I never had a problem with my previous Alpine unit. I don't have any wires running near the pedal or even in the engine bay. Any ideas?


----------



## fliplyricist1

^^ oh wow, sorry to hear man, that sounds horrendous 

my noise is just a very low audible 'whine' seeming to emanate from the headunit itself, that increases its pitch according to throttle response (and thus alternator response). it's not noticable at all if I have my volume over say...25

hope you find a fix for yours though, not sure if it's a pico but I definitely could not live with that kind of annoyance


----------



## fliplyricist1

http://cgi.ebay.com/1A-1-Amp-125V-P...698&_trkparms=39:1|65:15&_trksid=p3286.c0.m14

so are the types of pico fuses that'll work on the prs-8xx's?


----------



## tard

in the HU they are DSM, not much bigger than the ball tip on an ink pen and square. you'll notice the label of "fu 351" i believe, right close to it printed on the board.

in the 800, once you take the cd player portion out, have the face of the unit facing you, the fuse in is in the right rear corner on the board.

if you pull yours apart and take a pic, i'll draw an arrow to where it is.


that noise is horrid. there's another way to check if it's blown. try continuity between outer rca connection and the chassis of the HU. if none, the fuse is blown. make sure all rca's are not plugged into any amps, or else you'll get a reading of the amps preamp input resistance.


----------



## ngiing

i had the same problem last time but it couldn't stop my humming


----------



## JonMR2turbo

tard said:


> that noise is horrid. there's another way to check if it's blown. try continuity between outer rca connection and the chassis of the HU. if none, the fuse is blown. make sure all rca's are not plugged into any amps, or else you'll get a reading of the amps preamp input resistance.


How can I do that?


----------



## txbonds

JonMR2turbo said:


> How can I do that?


Simple way would be to take your multi meter and put it on the Ohms setting, then touch one probe to the headunit and the other to the RCA. If you get a reading, there is a connection. If you don't get a reading, there isn't.

I'm not an electrical person, but I think some meters are designed to test continuity.


----------



## jrwalte

txbonds said:


> I'm not an electrical person, but I think some meters are designed to test continuity.


Yes. Some have an audible test tone that'll go off if it is true, as well.


----------



## JonMR2turbo

txbonds said:


> Simple way would be to take your multi meter and put it on the Ohms setting, then touch one probe to the headunit and the other to the RCA. If you get a reading, there is a connection. If you don't get a reading, there isn't.
> 
> I'm not an electrical person, but I think some meters are designed to test continuity.


I did that and didn't get a reading. Hopefully the ebay store I bought it from will replace it for me again


----------



## abuyahoo

chad said:


> But 0 and 1 ohm resistors work great as fuses (Slo Blo), it's VERY common in tons of gear for protecting... from... get this.... GROUND OOPSIES! The only thing I would do different is to use a FlameProof resistor incase there's a BIG oopsie. This will keep the resistor from "flaming on" and getting that **** smoke all over the laser assembly and other components.


Hi,i'm new to these forums and i come from Australia,anyway i have a 960mp which is exhibiting the problems being discussed[yeah i hot swapped rca's too!]so ive dismantled my H/U can see the fuse[man its tiny],to me it just looks like a solid strip of metal,how the hell do i remove it to put in a resistor,looking at everyones diagrams they appear to have 2 seperate terminals with the fuse bridging the gap,mine just looks like a solid strip and i'm assuming thats cause the fuse is still in place,how do you remove it,your help would be much appreciated,cheers Reg


----------



## txbonds

abuyahoo said:


> Hi,i'm new to these forums and i come from Australia,anyway i have a 960mp which is exhibiting the problems being discussed[yeah i hot swapped rca's too!]so ive dismantled my H/U can see the fuse[man its tiny],to me it just looks like a solid strip of metal,how the hell do i remove it to put in a resistor,looking at everyones diagrams they appear to have 2 seperate terminals with the fuse bridging the gap,mine just looks like a solid strip and i'm assuming thats cause the fuse is still in place,how do you remove it,your help would be much appreciated,cheers Reg


Haven't had to do it myself, but my guess is you are going to need a very small solder iron tip to heat the solder pads enough to pull the pico fuse out of the board. The other option might be to use a desoldering iron to remove the solder on each side of the pico fuse, then you can solder in the resistor.

A desoldering iron is a specialty iron, that has a rubber bulb on it. You squeeze the rubber bulb, heat the solder with the iron, then release the bulb and it sucks the melted solder out of the joint. You can get them at stores like Radio Shack here in the states for pretty cheap.

If you have some nail clippers you might even be able to just cut the pico fuse off the board and then solder the resistor in place.

Good luck with it what ever way you end up going.


----------



## abuyahoo

txbonds said:


> Haven't had to do it myself, but my guess is you are going to need a very small solder iron tip to heat the solder pads enough to pull the pico fuse out of the board. The other option might be to use a desoldering iron to remove the solder on each side of the pico fuse, then you can solder in the resistor.
> 
> A desoldering iron is a specialty iron, that has a rubber bulb on it. You squeeze the rubber bulb, heat the solder with the iron, then release the bulb and it sucks the melted solder out of the joint. You can get them at stores like Radio Shack here in the states for pretty cheap.
> 
> If you have some nail clippers you might even be able to just cut the pico fuse off the board and then solder the resistor in place.
> 
> Good luck with it what ever way you end up going.


Hey thanks for that,i did happen to purchase a desoldering unit as a just in case i need it item before starting this project so will give it a shot,the nail clippers idea has lots of merit as the smallest needlenose pliers i have are just too big thanks again Reg


----------



## doktorspok

Hello all, my first post on the DIYMA forums. I showed up here because I have a Pioneer DEH-P3600 whose non-fading preouts died, and now my subs look like they're being defibrillated every 2 seconds or so. The system worked fine until my amp's power wire came disconnected, then when I hooked it back up a few weeks later, the HU preouts never worked right afterwards. The amp and subs tested fine.

Anyway, I disassembled the HU and found a pico fuse on the underside of the circuit board "FU353" to be open-circuited. Resistance between the ground plane of the HU and the ground surrounds of the RCAs was 1.638 M ohms. The "FU352" location was empty, so I didn't mess with it. I found a 10-ohm resistor and soldered it across the two planes, but realized a couple of things in the DEH-P3600:
1. The trick where people wrap bare copper around the preouts would accomplish the same thing as soldering the resistor across the fuse because you are connecting the same electrical nodes, just at different locations.
2. The bare copper wire trick may only need to be done to one RCA surround, not all four, because they're all connected to the same trace on the circuit board anyway.
3. If we're talking about grounding the RCA preouts to the chassis ground, don't most amplifiers already do this internally already? If so, wouldn't that eliminate the benefit of grounding the RCAs to the HU chassis ground? Or is there enough variation in the ground potential between the HU and the amp that it's necessary to ground at both locations to minimize noise entry?


----------



## elvisjer

I have two channels of my 960MP that pop when i turn on the HU....yes there's been hot swapping. Any experience with the 960mp?


----------



## chad

elvisjer said:


> I have two channels of my 960MP that pop when i turn on the HU....yes there's been hot swapping. Any experience with the 960mp?


Are those 2 channels on a different amplifier?

The pop on 2 thing is unlikely a fuse, the problem is usually global OR on an amplifier that is different in grounding the shield. Does it opo when switching CD tracks or any types of muting?


----------



## elvisjer

No popping except when turning on. What do you mean about the grounding? That didn't really make sense to me so rather than guess i'll just ask for an explanation


----------



## chad

elvisjer said:


> No popping except when turning on. What do you mean about the grounding? That didn't really make sense to me so rather than guess i'll just ask for an explanation


Some amplifiers have a differential input scheme, some use chassis ground, and some use "audio ground" which is usually isolated from chassis by some means.

Unfortunately thee is no standard


----------



## elvisjer

So im still a little lost on this though, what does this mean in relation to my setup and popping noises? What did i do wrong or what did I not do at all?


----------



## 60ndown

im guessing its your amp popping not the hu.

put a relay on the amp remote so it turns on after the hu.


----------



## elvisjer

well it looks like it may have actually popped for real now, im hearing the disc spin and pops all over! Any word on the fuse location and repairability on my HU?


----------



## ebrunn

Has Pioneer not recognized this as a problem? I just blew my fuse from the second time on my 880. I'm almost considering looking into getting a class action started for this crap.


----------



## chad

ebrunn said:


> Has Pioneer not recognized this as a problem? I just blew my fuse from the second time on my 880. I'm almost considering looking into getting a class action started for this crap.


Pioneer: "What problem? a fuse is for protection."


----------



## elvisjer

It seems like such an odd circuit, to put a surface mount fuse there, especially when they aren't making money off of warranty repairs of it. Maybe a lot of people ARE sending them in for repair, and a worker who knows the unit could replace that picofuse in 15 minutes tops which makes pioneer lots of cash. My 960 now stopped making the noises....this is so nerve wracking! Apparently the 960MP has burr-brown DACs in it?! I can't find much info on the history of this deck that i have. Where in the premier line was it and when?
: update :
I took it apart and found the fuse which did have a little bit of brown around the solder points looking like it had blown. It was a PAIN to get this thing apart, and i'm generally technically inclined. 12312388 screws in impossible to get out, and even harder to get in places. I jumped the fuse and the noise persisted but now a few days later is gone...odd.


----------



## trudgent

Hey there,

Im new to this forum but i have a pioneer DEH-P9650mp and i have only had it for a week and there is alot of unwanted noise coming from the preouts. It varys from popping about 3 times a second to humming. And when the motor is going i get really bad alternator whine. Do you think it could be a pico fuse? or something more serious. 

I have a bit of electronics knowledge so i think i would be capable of fixing it myself if thats what it is.

Any help would be much appreciated. thanks


----------



## WLDock

I find these Pioneer problems interesting. I have a friend that has a P9 combo and developed a lot of noise and alt whine. I really wonder if he blew something on the output of the DEQ-P9 processor? Even more interesting...he pulled the P9 and put a Pioneer Video unit in and said that the sound and overall midbass cleared up??
I really wonder if something is screwed up with his P9?


----------



## TheBigOne1

makes you wonder on Pioneer Video unit's


----------



## illnastyimpreza

I finaly replaced the ribbon cable in my Pioner DEH-P780MP, then disasembled the faceplate, and baked the MB in the oven for 1/2 hour. My changing songs & volume problem is gone, but now I have ****ing CRAZZY alternator whine ! WTF... 

is my pico use blown ??? whats wrong with this thing...


----------



## Dillinger939

First off, I'm glad I found this forum, as I've been getting alternator whine from my Avic N-2 for over a year now. I actually hardly notice it anymore until someone riding in my car mentions it. Sad I know. Anyways if someone was to do this "ghetto fabulous" pigtail fuse holder contraption what would you guys recomend as far as amperage? I have yet to attempt to locate this pico fuse, not even sure if there is enough surface/contact area for soldering something like that on to be viable. Just seems like a good solution, and at this point I'm not above stooping to that level. :blush:


----------



## yellowmustang

I'm pretty sure I've got the same issue with my Pioneer Avic D3 only it wasn't from hot swapping and was definitely my fault I accidently hit an RCA with a small power wire while doing some work. Prior to this I had just finished my kick panels and had zero noise when testing out the mid and tweet, after my screw up...crazy noise..horrible. Anyway after reading about all the problems people where having with their RCA outputs from hot swapping I'm hopping the fuse sensitivity is gonna be a saving grace for me.

First thing I did was check my rca grounds to the head unit chassis for continuitty.....none so on I pushed.

After popping off the top and taking out the four screws holding in the cd player portion this is what I had.










looking over this top board I checked a few of the little fuse looking deals with my meter for continuity across them and they were all good I figured this since the board at the bottom of the unit looked to be where the RCA came in.










looking down I saw these two with the white box around them and the exclamation point nearby hoping one of them was the issue I checked to see it the circuit was open....and to my relief one was. Knowing I couldn't solder in that tiny space I had to get the top board off. I looked at things and found that taking the face off then the top board looked to be the way to go.










After a few screws the face/screen came off and I unhooked the 2 ribbons and started on the top board only a couple screws a wire plug and I had it down to this










Now I could get to the fuse better










Hard to make out in the pictures I took but the board is labeled FU1702 I think and the actual fuse itself has SOC 72V T4A written on it. After looking into things I think these are called surface mount fuses and the one in question is a slow blow, 4 amp fuse. My plan is to run a couple small wires from each side of fuse on the board into a small 3AG fuse. 

Hopefully this will help others with different pioneer units other then the ones already talked about with this issue. It was really pretty easy to take apart....so far...... as its not fixed/soldered yet. Better then the 200 plus shipping to and from that pioneer wanted to look at it.


----------



## chad

Whoa, how the hell does hot swapping RCA's blow a 4A slow blow fuse?


----------



## yellowmustang

> Whoa, how the hell does hot swapping RCA's blow a 4A slow blow fuse?





> I accidently hit an RCA with a small power wire while doing some work


In regards to my case it definetly wasn't from hot swapping as I had read about the problem pioneers had with that.....but maybe the units people have had trouble with use a much smaller/sensitive type of fuse.

Both the fuses near the rca plug have T4A written on them so I'm assuming thats what they are...?


----------



## illnastyimpreza

^ awesome, thanks for the PICTURE posts. I"m gonna wait to hear about yours working, and hopfully some shots of how you hooked up the external fuse holder, before I attempt it on mine


----------



## yellowmustang

I'm waiting to round up a few parts and then I'll post some pictures and see if it works.


----------



## yellowmustang

K...so it took a while to get the things I needed but I got them and went to work....

Here is the 3AG fuse holder that I,m gonna use with a 4 amp slow blow fuse since that what the original surface mount fuse was.










It requires a 1/2 inch hole, so I tried to figure the best place to mount it and marked where to drill the hole.










Hole drilled....










The fuse holder mounted to the back portion of the case and put in position
on the unit.










Now that I know things were gonna fit all I had to do was cut the wires I was planning on using to length. Then solder them on to each side of the surface/pico fuse that was open. 










Now I soldered the other ends to the fuse holder leads and heat shrinked them because the prongs were rather large and figured it be best they were insulated incase they touched the bottom of the middle case/board in the unit.










Now I just put it all back together the opposite of the way I took it apart.....and put it back in the car to see if this whole process worked. I turned the car on and was happy to see that the screen still worked and I had volume. I got some music going I was pretty excited to hear things back the way they were before my RCA trouble.

Picture of the fuse holder on the back of the unit after I put it all back together










I definitely recommend trying this yourself to anyone having noise issues with their pioneer RCA outputs. All in all it really wasn't too hard to do this and all the surface mount fuses internally are pretty easy to spot and test once the unit is apart.


----------



## illnastyimpreza

awesome ! I"m doin this next week ! thanks for the motivation !


----------



## chad

Although I still feel that it's sad that the fix is necessary..... 

KUDOS, that's usin' the 'ol noggin riiiaaat thar!

The spirit of DIY!


----------



## covsound1

this is my first post i have the same hu in my ford van and sawped a amp while power was on my bad. you are the man this looks like the best fix for me. no more hot sawping for me.


----------



## illnastyimpreza

hey yellowmustang, where did you get your little fuse holder and such ?


----------



## yellowmustang

I just ordered all the stuff I needed for this from parts-express.com. On there homepage click electrictronic parts on the left and then go to fuse holders.


----------



## brenttor

Hey I hope someone can help me..
I have been lurkin and figured i had the same problem (blown pico fuse) with my AVIC-D1..
so I opened up the sucker and took a look.. couldnt find any "FUS**"'s or any trigles with !'s in them.. but i did find these 3 guys that look like they blew up..
i dont wana take it to the shop it wont be worth it...
i think they are labeled D1402, D1409 and whatever..

pleeease help me out..
any input is appreciated


----------



## brenttor

Sorry 
a more specific picture:


----------



## chad

brenttor said:


> Sorry
> a more specific picture:


A 6 pack says that those are Muting FETS.


----------



## brenttor

how can i be sure? is there a schematic to the D1?
what would cause this problem?
and if they are can i buy replacements and solder them myself?


----------



## chad

What attaches to that white connector?


----------



## brenttor

chad said:


> What attaches to that white connector?


RCAs:
-subs
-front
-rear
-video
-back up camera


----------



## brenttor

no ideas on how this can be fixed?
besides buying a new deck....?


----------



## chad

I'll bet they are fets then. What needs to be done is that that area needs to be cleaned up with denatured alcohol and you need to look for burnt traces on either side of the board. Then you need service docs or a working unit or someone with a working unit to find out indeed what that part is. Then you need to be quite handy with replacing SMT components 

There are repair places, some may even do a flat rate repair, BUT YOU MUST FIND OUT WHAT CAUSED THESE PROBLEMS IN THE FIRST PLACE!!!!!!!

The scavenger in me goes.... hmmmm... a handyman's special


----------



## brenttor

you making an offer?


----------



## chad

brenttor said:


> you making an offer?


Wish I could, the only thing I could fit it in is the wifes Pilot and the BJ to mod ratio is not there at the moment, neither is the funding


----------



## illnastyimpreza

chad said:


> Wish I could, the only thing I could fit it in is the wifes Pilot and the BJ to mod ratio is not there at the moment, neither is the funding


hahahahah yeah my girlfriend used to love when I modded her old 95 Subaru...but now that she has a nice new Maxima she doesn't want anymore mods  O well...


----------



## brenttor

you think i can run this safely without any rca's or amps?
i got a truck it will fit in..


----------



## chad

brenttor said:


> you think i can run this safely without any rca's or amps?
> i got a truck it will fit in..


I don't see why not as long as the internal amplification still works fine.


----------



## gijoe

Wish me luck everyone, I'm going in. I've done a little soldering before, but nothing this small. Any tips? Should I just solder the new resistor to the legs of the existing one? Do I need to make sure that the wires are in full contact, or will the solder carry the current effectively?


----------



## illnastyimpreza

ok I just pulled the top off my DEH-780MP and it looks tough to figure out the RIGHT way to take this ***** apart.

Can someone link me to the disasembly guide??


----------



## qstarin

Hmm .... I've got a Pioneer DEH-4900IB or something similar that's SCREAMING noise out of 1 channel.

Just became aware of this "pico fuse issue", so I guess I'll have to take mine apart and have a looksee. Maybe its salvageable.

I don't know when exactly it happened, since the problem wasn't happening right before it was swapped out, but was the next time I tried to install it. Dang, I break a lot of audio equip.


----------



## chad

If it's a pico issue it will be present on all channels


----------



## qstarin

shoot. Well, I guess I'll still tear it apart out of curiosity, but I'm no fan of smd soldering, and I won't pay to fix it, so it'll probably end up in the trash.


----------



## illnastyimpreza

where can I find the disassembly and assembly guide ?


----------



## Raisin

dAMN! Nice Thread. One I've been looking for.

After all the fuss from buying a really cheap 65BT, i got "NOISE" that i never encounter with my old Kenwood. 

This could be the source of that damn noise i got. no wonder that jackA#! sold it cheap (owned only for a couple month) sold it just 1/3 the price. 

just about to toss it away after find out the HU caused the noise after month of troubleshooting. 

Going to tear it up! Pronto! and laugh at the dude who sold it afterwards.


----------



## DraKhen99

Wow, who knew?

I've been running Pioneer HUs for the last 8 years, and I've never had a problem! I don't hot-swap RCAs or any other cabling, I always have the car off and the keys out of the ignition first.

My first was a 940MP, which was in cars I totalled, and a 3rd, and was 6 years old when I finally had to let it go (couldn't find the stock radio for a car I was trading in).

My next was an 880, professionally installed. (I just spoke to the installer, who said he grounded the unit to the wiring harness, and didn't do anything else special for grounding, and I haven't had a problem with that stereo in the 2 years it's been installed in my car.)

Then, in my 2nd vehicle (which I did all the work on), was a 4900, a 7700, and right now a 6000. 

Yesterday I bought an 880 to put into my 2nd vehicle, and was just going to run the wires like I normally do: power to power, ant. to ant., remote turn-on to remote turn-on, and ground wire to ground wire. I've never run a separate ground wire to the chassis, always just clipped the ring and spliced into the wiring harness.

I always have the car turned off (keys out of the ignition). If I just run the wires like I always have, and make sure that everything is connected before putting the key in the ignition, I should be OK, right? I was thinking that I'd do everything normally, but in the case of the ground wire, I'd just find a screw (that goes into metal) or something close by to hook that too.

Will I be OK without disconnecting the (-) battery terminal? I would think so, since there isn't any power running in the harness when the car is off and keys are out of the ignition, right?

Thanks,

-John


----------



## 1hawaii50

DraKhen99 said:


> Will I be OK without disconnecting the (-) battery terminal? I would think so, since there isn't any power running in the harness when the car is off and keys are out of the ignition, right?
> 
> Thanks,
> 
> -John


Why take the chance? It takes me 2 minutes to pop the hood, get a socket, and pull the battery cable....cheap insurance!


----------



## DraKhen99

1hawaii50 said:


> Why take the chance? It takes me 2 minutes to pop the hood, get a socket, and pull the battery cable....cheap insurance!


just thought I'd let everyone know that I installed the 880 tonight, and I didn't have to take any extra precautions, just took the keys out of the ignition and went to town! Install went well, and everything works just fine; PAC-SWIPS, XM tuner, iPod connection. No hissing, popping, or whine, just clean, beautiful sound 

John


----------



## 1hawaii50

DraKhen99 said:


> just thought I'd let everyone know that I installed the 880 tonight, and I didn't have to take any extra precautions, just took the keys out of the ignition and went to town! Install went well, and everything works just fine; PAC-SWIPS, XM tuner, iPod connection. No hissing, popping, or whine, just clean, beautiful sound
> 
> John


John, 

Great to know that it all went well!


----------



## DraKhen99

1hawaii50 said:


> John,
> 
> Great to know that it all went well!


Thanks, me too! LOL

Now to fine-tune the T/A, but the AutoEQ did a good enough job. With the distance between the woofers and tweeters up front, the T/A has no real idea how far away from the driver they are. That ought to be a fun project too, haha!

-John


----------



## M-Dub

The other day my amp made a loud pop and the music stopped. I turned the key off, then on again. Music came back but now I have alt whine . 

I was sure something in the amp blew because of the loud pop coming from the back (I have no rear fill).

After some trouble shooting I realized the noise was coming from the 880. I swapped it with my old DEX-P1R and no more noise!

It seems the amp went into protect mode. The loud pop was probably the internal circuit breaker. The amp is fine.

I DID NOT TOUCH RCA's! the RCA's didn't move. No other fuses blew.

My 880prs may or may not be under warrenty. I really don't want to wait 2+ weeks to get it back. 

I'm thinking of voiding the warrenty by putting some orange gel filters over the LED's anyway.

So it looks like I'm goin in.

Wish me luck!


----------



## M-Dub

Woot! Fixed it! 

I just buried the pico fuse under a ball of solder, essentially making a jumper wire. 

No more noise! 

Except now I don't have the benefit of fusing. I better be careful. 
No more extra lives


----------



## CrackedHead

Another one bites the dust! My "installer" hot swapped RCA's while hooking up a four channel amplifier to my Pioneer DEH-7950UB head unit and now I have the noise:dead:. 

Does the head unit have separate pico fuses for each set of preouts ? 

I ask because I never had any rear fill (so the preouts for the rear channel have never been hooked up to anything). Could the pico fuses for the rear channel still be intact?

I am going to try feeding the front speakers with the signal from the rear preouts but the cables are a little hard to get to -- Would appreciate if someone could tell me if this will help. Thanks.


----------



## kyheng

Nope, it just have 1 single pico fuse.
Fast/temporary repair : add a ground on RCA back to HU's chasis.
proper way : send back to Pioneer SC o someone good in electronics to repair.


----------



## chad

most proper way, avoid pioneer.


----------



## TAXI_89

great thread. learned alot today.

my question - I have a 860 in my toy car, and just picked up a used one for my DD. and its got the noise. its terrrible. i got the radio out of the car today, and pulled it apart. ive looked over the board and the connectors, and dont see anything obvious. so if i wanted to fix this problem myself, which i am perfectly capable of doing, lotsa soldering experience and access to parts, what am i looking for? i find no FUxxx marked on the board, and im just not that good at trouble shooting. if someone knows the marking of the picofuse or resistor i need to replace, thatd be awesome, but a pic would be better. 

thanks!


----------



## Lars Ulriched

chad said:


> most proper way, avoid pioneer.


Was about to get P80RSII....lucky I took Clarion HX-D2....will not turn back....


----------



## tanakasan

kyheng said:


> Nope, it just have 1 single pico fuse.
> Fast/temporary repair : add a ground on RCA back to HU's chasis.
> proper way : send back to Pioneer SC o someone good in electronics to repair.


Fast/temporary repair :"bandaids" 97% of the noise out
Proper way :Back to OEM status, but vulnerable to another pop and repeat pico problem cycle
*Quick and effective repair : solder ball that pico fuse!*

Mine has a repair and it functions fine. I also added a radio chassis to ground wire. No problemos since.

Robert


----------



## M-Dub

tanakasan said:


> *Quick and effective repair : solder ball that pico fuse!*


Quick and effective indeed. Still no issues. I'll update this thread if something bad happens.

I hope your amp never goes into protect mode.


----------



## tanakasan

M-Dub said:


> I hope your amp never goes into protect mode.


Some one else here solder balled the pico!

Why, what would happen if an amp went into protect mode? I ask b/c my 5 y/o eD Nine.2x did just that. Was fine, then started sounding "fuzzy" every so many starts, then 100% fuzzy, then finally would turn on/green, light up red/protect then all off. Replaced it with a Zuki from the boards and am 1000% happier!

Back OT, my HU is fine, system is fine, speakers are fine...whats *supposed* to happen?

Robert


----------



## M-Dub

tanakasan said:


> Some one else here solder balled the pico!
> 
> Why, what would happen if an amp went into protect mode? I ask b/c my 5 y/o eD Nine.2x did just that. Was fine, then started sounding "fuzzy" every so many starts, then 100% fuzzy, then finally would turn on/green, light up red/protect then all off. Replaced it with a Zuki from the boards and am 1000% happier!
> 
> Back OT, my HU is fine, system is fine, speakers are fine...whats *supposed* to happen?
> 
> Robert


Well we know that messing with the RCAs while hooked up to power blows the pico. I'm saying that an unhappy amp will also blow it. Mine happened while I was driving, not wiring. Everything was sounding good, then I heard a a click from my amp compartment, then there was only bass. Pulled over and turned the car off then on. Mids and highs came back along with the noise. The amp died a month latter. I can happen.


----------



## chad

I don't see how a malfunctioning amplifier can crack a pico fuse.


----------



## tanakasan

^^It did not in my case...

Robert


----------



## gompka

Does anyone still have the repair manual? The link is long gone now. I have been having this problem for years and I have just been grounding the rca's, I will be looking at the pico fuse soon, but also have a problem with extremely weak am signals, thought I could knock out both things at once if I had a manual.


----------



## M-Dub

gompka said:


> Does anyone still have the repair manual? The link is long gone now. I have been having this problem for years and I have just been grounding the rca's, I will be looking at the pico fuse soon, but also have a problem with extremely weak am signals, thought I could knock out both things at once if I had a manual.


My Retrevo - My Manuals


----------



## kyheng

Nope, FM is something you cannot do..... As for pico fuse, you can get a very thin wire which can act as a fuse also. A pioneer 4A fuse can cost you some $4 while a 5A fuse you can get from local stores for <$.50.


----------



## telegogo

great thread. learned alot today.


----------



## gompka

M-Dub said:


> My Retrevo - My Manuals


Thanks for the quick reply, but no go onn that website. It just shows me "
add a manual"


----------



## M-Dub

gompka said:


> Thanks for the quick reply, but no go onn that website. It just shows me "
> add a manual"


Odd, I just tested it with a phony email before my first reply. Worked. PM me your email address and I'll send it to you.


----------



## tinctorus

Would a better solution to just using a solder be to mod the back of the radio and place an inline fuse holder mounted to the back chasis of the radio???

Similar to how some radios have a 10a fuse at the power plug but this would be mounted to the back of the radio and JUST be for the pico fuse???
This way you are STILL protected with a fuse and it is easily replaceable if it should ever pop again?


----------



## kyheng

Pico fuse is measured on a 0.*A rating.


----------



## M-Dub

What does the pico fuse actually protect? It seams like we're just trying to protect the fuse itself. That's circular. I jumped my blown pico fuse with a small blob of solder with no ill effects. I've even hot swapped RCAs


----------



## chad

M-Dub said:


> What does the pico fuse actually protect?


It ties the RCA sleeve from chassis ground in case an amplifier that has it's RCA sleeve tied to chassis ground (rare these days) loses the ground connection and it attempts to derive ground thru the head-unit ground down the RCA.

When pioneer steps out of the 80's and realizes that nearly NO modern amps are configured this way we will be all good. If the input on a more modern amp is NOT differential then the shield is floated from the chassis by tying it to the center tap of the power supply transformer.


----------



## chad

the link-backs on this thread are long and distinguished... like my man appendage.


----------



## tanakasan

My PRS880 pico repair is on page 4, post #86!

Done 9/07/07 still running fine w/o any ill effects. 

Robert


----------



## razholio

chad said:


> the link-backs on this thread are long and distinguished... like my man appendage.


and like your disdain for pioneer pico fuses.  I'm actually really interested in your opinion on this one, Chad. I have an 880, and I accidentally grounded the hot lead of one output channel of a soundstream D60 (I know, shame on me) to the chassis (tight install), and instead of gracefully blowing a fuse, the D60 shoved a metric assload down the RCA sleeve through my 880's pico, blowing it wide open.

I took it to a great local shop and when I asked if they would wire up an external fuse for me, the guy said something serious musta happened (bad wiring) because that pico is rated at 4amps, and those sleeves shouldn't see anything that high, ever. They repaired it under warranty, btw.

So, I wonder, what caused the D60 to dump to the RCA sleeve? it had its own perfectly good ground, and since the traces on the board in the 880 won't take much more than 4amps, what's wrong with the pico fuse protecting them?


----------



## tanakasan

razholio said:


> because that pico is rated at 4amps, and those sleeves shouldn't see anything that high, ever.


I thought that the picos were in the .3~.5A range?!? Thats what causes the issue b/c they are way too small of a value. I *believe* the Pio factory fix uses a much larger value upon replacement.

Take with a grain of salt, I am a Special FX tech, not an EE.

Robert


----------



## Pinenut

Great Thread! I am following Yellow Mustangs post since I also have a D3 with the same issues. One question though, would the 4AMP slow blow fuse he suggest be too high of a rating? I wasn't sure so I got a 1 Amp as well. I will try both. Anyone know the correct rating of the pico fuse in the D3?


DAMN! That wasn't it I guess. I fused it just like mustang's thread and still got noise. Then I blobbed it and still! What else could be causing the noise?? Grounds all look good, RCA's seperated etc...


----------



## gompka

Well I have been having noise since I bought my p880 and I had it ghetto rigged for years with a ground wire around the rca's, also my AM radio never worked. I checked the pico, and sure enough it was blown. So, I went ahead and added a panel mount fuse holder (5mm x 20mm). My p880 sounds great now! And my AM radio is working!


----------



## chad

the pico must also protect the coax shield which AM MUST have..... yet another source of issues, especially if the antenna is amplified and NOT tied to ground at the roof or fender.


----------



## gompka

chad said:


> the pico must also protect the coax shield which AM MUST have..... yet another source of issues, especially if the antenna is amplified and NOT tied to ground at the roof or fender.


That would explain why I had FM but not AM. I know my scion tc has an amplified antenna, I checked and it is grounded to the fender. Also, its really weird what happens when i remove the fuse from the holder i made. I can have the p880 hooked up to an amp, and remove the p880 from its harness so all that is attached is the rca's, no power. The p880 induces crazy noise into the amp, and if I touch the chasis of the p880 it makes even more noise. If i take the fuse out with the p880 hooked to power and rca's then I have to turn it up to about 50 to barely get recognizable music above all the noise. Any theories on this Chad?


----------



## LipschitzWrath

Okay guys, I need your expertise. I am pretty good with car electronics but I am having one HELL of a time getting this one figured out. Car is a 1998 Grand Cherokee and deck is a Pioneer DEH-P710BT (Premier).

So I installed a completely new audio system last weekend and everything is working great, except for the dreaded alternator whine. I started looking around the 'net to get some ideas of how to remedy this and I stumble upon the sleeping giant that is the "Pioneer Pico Fuse Problem". I had no idea. And suddenly, I'm crapping my pants because I seem to remember hot-swapping my RCA's.

Anyways, I pulled the deck last night and the first thing I did was tested for continuity between the RCA shield and the HU chassis. Much to my surprise, I had it. My resistance is 0.6 ohms. All of the sudden, I am stuck and I haven't even made it past step one. I decide to open up the head unit anyways to see if there is a bad fuse. Well, I got it open but I'll be ****ed if I can find any fuses. I can't find anything on the board labeled "FUxxx". In fact, all I found that I could even conceivably believe to be a fuse was something labeled "P401". I checked it for continuity and it was open. However, when I switched my DMM over to resistance mode, I got a resistance of 2.2 megaohms or thereabouts.

So at this point, I have no idea what I am doing and put the head unit back together. I put it back in the car and fired the system back up. No surprise - alternator whine is still there. So now I am thinking it is NOT the head unit. Even though I knew it wouldn't help, I tried the "ghetto pico fuse fix" and wrapped speaker wire around the RCA shields to chassis. Nothing. I start trying other things. I ran a 14-ga wire from the chassis to the amplifier grounding point (under the rear seat) and that didn't help.

While we are on the subject (and I don't know if this is pertinent to the discussion), let me mention something weird. So, I am running this ground wire from the black wire on the main harness of the deck back to the amp grounding point. When that doesn't work, I disconnected the wire, thinking that it would kill the HU. It did NOT. The head unit kept on running. I can't for the life of me figure out how. I mean, if the black wire in the harness isn't grounded, where is this thing getting its ground??? And I don't think there is any metal-on-metal contact. The mounting kit is plastic and completely insulates the deck from the dash. Like I said, dunno if it's related.

So, I am stuck. It doesn't APPEAR to be a Pico Fuse problem but I don't claim to be an expert. Alternatively, if someone knows the location of the Pico fuse on a 7100BT/710BT, I would be willing to check it again.

Some other info on my Jeep. I have done the "Big 3" and then some. First off, I took every factory cable (6-gauge) and supplemented (NOT replaced) that with an aftermarket 4-gauge cable. I have a dual-terminal Optima so I decided to make use of the side terminals, too. The positive is a 1/0-gauge cable running to my amps (two Infinity Kappa Five's). I then ran a 1/0-gauge cable from the neg side terminal and took that to a bolt on the frame, then ran a 1/0-gauge cable from that same bolt on the frame to an engine bolt. All in all, I am pretty sure the grounding is solid, but you guys tell me.

Also, there are RCA cables running down both sides of the Jeep so there is a set that parallels the 1/0-gauge power cable. However, the RCA cables are on the interior of the vehicle and the power cable is on the exterior of the vehicle (actually, it's running down the inside of the box frame rail). Think I could be picking up interference from that, even though there is the sheet metal of the floor pan separating them?

PLEASE HELP!


----------



## razholio

LipschitzWrath said:


> Also, there are RCA cables running down both sides of the Jeep so there is a set that parallels the 1/0-gauge power cable. However, the RCA cables are on the interior of the vehicle and the power cable is on the exterior of the vehicle (actually, it's running down the inside of the box frame rail). Think I could be picking up interference from that, even though there is the sheet metal of the floor pan separating them?
> 
> PLEASE HELP!


it doesn't appear to be a problem with the fuse, tho that DCR value is rediculously high for a fuse. are you sure that's not milli-ohms with a little 'm'?

The HU needs a good solid ground (best in the vehicle), but doesn't need to be grounded at the same spot as your amps. The HU will act as the common ground for the entire line-level signal path. Are you using good quality *shielded* RCA cables? When I've got my pico fuse in one piece, and all power sensibly routed (>12" parallel from RCA with perpendicular crossings), I get *no* noise. I've done some hokey **** with piggy backing power off my tweeter amp for a temp hookup to another amp and gotten noise.


----------



## LipschitzWrath

razholio said:


> it doesn't appear to be a problem with the fuse, tho that DCR value is rediculously high for a fuse. are you sure that's not milli-ohms with a little 'm'?
> 
> The HU needs a good solid ground (best in the vehicle), but doesn't need to be grounded at the same spot as your amps. The HU will act as the common ground for the entire line-level signal path. Are you using good quality *shielded* RCA cables? When I've got my pico fuse in one piece, and all power sensibly routed (>12" parallel from RCA with perpendicular crossings), I get *no* noise. I've done some hokey **** with piggy backing power off my tweeter amp for a temp hookup to another amp and gotten noise.


Thanks for the comments. Here is my response.

First off, I don't even know if that is a fuse. Like I said, the number on the board was like "P401" or something like that. It was definitely a P. I thought the fuses were labeled FUxxx. I can't find anything on the board labeled FU. So I'm not sure if that was a fuse or something else. And yes, I am sure it was mega and not milli - my day job is as an engineer. :laugh:

The head unit ground has that weird thing going on where I can disconnect it altogether and the HU stays on. I dunno WTF is going on there. But I ran a temp 14-ga wire all the way to the amp grounding location (to eliminate potential difference) and that didn't even help.

As far as the interconnects, these are what I have: Stinger Pro 3 SPI6312 12' 6 Channel RCA Interconnects

The ones running down the passenger's side probably are within 12" of the power cable, but like I said, the floor pan separates them (RCA's interior, power cable exterior). I thought that would stop any inductive interference (wouldn't it?).

I suppose the next step is to disconnect the RCA's one by one and see when/if the noise goes away. If disconnecting the passenger side only cleans it up, then maybe I AM getting interference from having them running parallel.


----------



## LipschitzWrath

Does a DEH-P710BT even have a pico fuse?


----------



## chad

If you have continuity (LOW RESISTANCE) between the sleeve of the RCA's and the chassis, with nothing connected to the outputs of the head-unit then it's not a pico fuse issue.


----------



## LipschitzWrath

chad said:


> If you have continuity (LOW RESISTANCE) between the sleeve of the RCA's and the chassis, with nothing connected to the outputs of the head-unit then it's not a pico fuse issue.


That's what I figured. And like I said, I am getting 0.6 ohms between the two. So I think that qualifies as having a good pico fuse.

Normally, I'd do the dance of victory at this point. However, since I am unable to locate anything else that is causing problems, I am extremely frustrated and confused.


----------



## chad

For the love of god, do not disconnect he headunit ground, that's precisely WHY the pico fuse is there. To blow when people do that.

But chances are it was getting ground from the antenna sleeve.


----------



## chad

how bad ins the alternator whine, is it obnoxious or jsut there, can you hear a thump when muting the volume? can you hear the CD transport changing tracks, etc?


----------



## LipschitzWrath

chad said:


> how bad ins the alternator whine, is it obnoxious or jsut there, can you hear a thump when muting the volume? can you hear the CD transport changing tracks, etc?


It's just there. No thumping or CD transport, or anything else for that matter. You can only hear it when you have the audio down. Not off, but down (volume < 10 or so). Then you can hear it whining consistent with alternator RPM.

WTH do you think it could be?

Right now, it is so frustrating that I am bordering on buying an Audio Control DQL-8, using the speaker level outputs from the deck to feed it, and then running my RCA patch cables from there.


----------



## ryan s

(Don't know if I posted it already in here...if so, bear with me :laugh: )

I had a whine with my old Pioneer unit, and measured the Pico as functional. Next step was to make _sure _the RCAs were away from the antenna lead, and I routed the power wire well away from the electronics in the driver's side kick panel for good measure. 

Also used a dedicated ground for the headunit instead of using the stock harness.

Et voila...silence 

Since your Pico measures fine, it's down to an install issue (IME).


----------



## chad

LipschitzWrath said:


> It's just there. No thumping or CD transport, or anything else for that matter. You can only hear it when you have the audio down. Not off, but down (volume < 10 or so). Then you can hear it whining consistent with alternator RPM.
> 
> WTH do you think it could be?
> 
> Right now, it is so frustrating that I am bordering on buying an Audio Control DQL-8, using the speaker level outputs from the deck to feed it, and then running my RCA patch cables from there.


do you still have whine with the volume at 0? I know that sounds stupid but bear with me. The reason I ask is because at 0 it likely engages Muting FET's that drops the pin to ground or close to ground on the output side.


----------



## LipschitzWrath

ryan s said:


> (Don't know if I posted it already in here...if so, bear with me :laugh: )
> 
> I had a whine with my old Pioneer unit, and measured the Pico as functional. Next step was to make _sure _the RCAs were away from the antenna lead, and I routed the power wire well away from the electronics in the driver's side kick panel for good measure.
> 
> Also used a dedicated ground for the headunit instead of using the stock harness.
> 
> Et voila...silence
> 
> Since your Pico measures fine, it's down to an install issue (IME).


^^^ That sucks. And here I thought that I did a great install.

How do I not cross the antenna lead? THe damn this is back there, right below the RCA ports.



chad said:


> do you still have whine with the volume at 0? I know that sounds stupid but bear with me. The reason I ask is because at 0 it likely engages Muting FET's that drops the pin to ground or close to ground on the output side.


I don't have access to my vehicle right now so I can't say for sure. I'll check it when I get home.

What are the implications in each case? What does it mean if it still is there at volume 0? What about if it goes away?


----------



## LipschitzWrath

One thing that may or may not be useful in this discussion is that when I hit the "mute" button on the head unit, the music stops but the whine remains. I found that out last night. I don't know if that gives you the answer you were looking for with the 0 volume question but, hey, posting it couldn't hurt.

I'd really like to get this figured out.


----------



## chad

That answers the question.

When you apply the brakes do you hear a slight pop? is there a whine in there that does NOT change with pitch, maybe under the alternator whine?


----------



## LipschitzWrath

chad said:


> That answers the question.
> 
> When you apply the brakes do you hear a slight pop? is there a whine in there that does NOT change with pitch, maybe under the alternator whine?


No pop with brake application that I can hear. No whine underneath. If the engine is not running, I get no noise that I can detect.


----------



## chad

I was looking for brake lights and fuel pump 

This is sometimes SUCH a pain in the ass man, hang in there.


----------



## LipschitzWrath

chad said:


> I was looking for brake lights and fuel pump
> 
> This is sometimes SUCH a pain in the ass man, hang in there.


Oh I'm not going anywhere. I will be the pimple on the ass off this forum until my alternator whine is gone, lol.

Now, let's pretend for a moment that it was one of those two. Remedy?

Maybe I'll try it anyways. At this point, I'll try anything. Did you see the link to my interconnects above? Are they high enough quality or should I be considering some new ones?


----------



## chad

I was looking for issues regarding induction ont he signal lines, some vehicles have VERY noisy electrical harnesses. It's best to avoid them at all cost, screw a bunch of amp wire it's the damn car's harness that can cause you grief more often or not.


----------



## LipschitzWrath

chad said:


> I was looking for brake lights and fuel pump
> 
> This is sometimes SUCH a pain in the ass man, hang in there.


And, admittedly, I haven't given you guys a ton to work with here. When I get home in a couple hours, I'll do some more systematic diagnosis. Start from the amp and disconnect the RCA's. See if disconnecting a particular side/channel helps.

Here's my setup right now

6 y-adapters (Stinger SPI23YF) connected to the back of the deck ---> each side to 12-ft 6-channel interconnect (Stinger SPI6312) ---> Infinity Kappa Five Amplifier

At first, I didn't have the connections to the y-adapters insulated and I thought it might be coming in on that. However, last night I pulled the dash back apart and wrapped them all in elec tape. No help.

Something else I'll be honest with. Last weekend, when I was putting the jeep back together, I accidentally sank a screw through the middle of the passenger side interconnect (the cable is flat, not round) underneath a trim panel. I was getting crazy noise until I figured that out. I pulled the cable back out and it doesn't appear that any major damage was done. Think this could be the culprit?

Like I said, I will try a more systematic approach tonight. Let me know if there is anything else you would like me to test. I will post my finidings either tonight or in the morning.


----------



## LipschitzWrath

chad said:


> I was looking for issues regarding induction ont he signal lines, some vehicles have VERY noisy electrical harnesses. It's best to avoid them at all cost, screw a bunch of amp wire it's the damn car's harness that can cause you grief more often or not.


Now that you mention it, I have retrofitted HID's into my reverse lights. When I flip them on, I can hear a constant noise. Doesn't really bother me though because I don't do much hardcore jamming in reverse.


----------



## chad

now we are getting somewhere!

I run BALANCED in my car and still had to avoid the wiring harness


----------



## LipschitzWrath

chad said:


> now we are getting somewhere!
> 
> I run BALANCED in my car and still had to avoid the wiring harness


What is your comment in reference to? The reverse HID's or the y-adapters? What do you mean balanced? I don't really understand that. Help me out here Chad!

And if you mean avoiding the car's wiring harness, there is no getting around that. There is a big fat bundle of wires running down BOTH sides of this Jeep (so much for a multiplex wiring system reducing harness complexity, BTW ). I suppose I could run it down the center, but really? Come on!


----------



## chad

the reverse lights buzz.

Balanced is a LONG story, but it's a way to run twisted pair and an inverting receiver to reduce noise using Common Mode Rejection (CMR)


----------



## LipschitzWrath

chad said:


> the reverse lights buzz.
> 
> Balanced is a LONG story, but it's a way to run twisted pair and an inverting receiver to reduce noise using Common Mode Rejection (CMR)


Like I said, the reverse light buzz doesn't really bother me. What's the fix? Avoid all chances and run it down the center? That's really gonna suck the big one if I gotta do that.

So are you now thinking that the vehicle's wiring harness is what is causing the interference? If so, I suppose I could temporarily run the interconnects over the seats down the center to test if that is the culprit.

WTF, Stinger?!?!? "Triple-shielded and twisted-pair" isn't good enough?

If I gotta re-route that cable then I have just decided - I'm going up the pillar and running my cables under the headliner. Cleaner and easier that way. The flat design of those stinger cables should make that a possibility, too.


----------



## chad

LipschitzWrath said:


> If so, I suppose I could temporarily run the interconnects over the seats down the center to test if that is the culprit.


totally worth a shot


----------



## LipschitzWrath

chad said:


> totally worth a shot


*****UPDATE*****

I've isolated the problem, though I have exactly ZERO idea how to fix it.

Okay, so I pretty much have my Jeep dismantled down to the point I had it when I was installing the system. I played around with the interconnects and this and that and here is what I found:

The noise is coming from my sound bar speakers!

Allow me to explain. Both of my amps are Infinity Kappa Five, 5-channel amplifiers. On my right amp, I run my front door speakers, rear door speakers, and right sub. On my left amp, I run nothing on the front channels, my sound bar speakers on the rear channels, and my left sub on the sub channel. You see, this Grand Cherokee is a 5.9 Limited, so it has the additional component speakers in a sound bar above the hatch area. I replaced those with some Infinity Kappa 60.9cs speakers.

Anyways, no matter where I run the interconnects or what they are hooked up to, I get noise. That's when I kinda noticed that the noise was coming from the sound bar speakers. I figured it might be in the rear low-level circuit, so I plugged some front channle interconnects in - still had noise. At this point, I decide to unhook the speaker wires running to the sound bar speakers - BINGO! Beautiful, golden silence!

Now, the offender has been identified, but I have no idea why it is happening. Furthermore, I haven't the faintest how to fix it. You think it is coming from the speaker wires that are bundled with a whole bunch of other wires? What should I try next???

I think the first thing I'll do is jump the speaker wires over to the front channels and see if the problem is exclusive to the rear channel of that particular amp. If not, then it is def the speakers. Maybe run some dedicated speaker wire and see if that fixes it???


*****UPDATE AGAIN*****

Just swapped over to the front channels of that amp - same noise. So, that rules out the amp (unless the entire amp is hosed). In the morning I will drop the sound bar down and toy with that. I'll run some different speaker wire to rule out the factory wiring. If that doesn't fix it, that either means the amp or the speakers are blown, right? God, I hope it's neither of those two. Fingers crossed!!!


----------



## nsaspook

LipschitzWrath said:


> That's what I figured. And like I said, I am getting 0.6 ohms between the two. So I think that qualifies as having a good pico fuse.
> 
> Normally, I'd do the dance of victory at this point. However, since I am unable to locate anything else that is causing problems, I am extremely frustrated and confused.


How old is the battery? Sometimes the whine is from excess ripple because of poor battery filtering due to high DCR from age or a failing alternator struggling to keep it charged.


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## dch828

There's a good write-up on avic411.com forums as well. I think either that forum or elitecaraudio forum has some great pictures. Basically, it is usually the pico fuses. The write-ups explain how to bypass the fuses. You can either just bypass it with a small resistor or add your own fuse. I saw one guy that ran a panel mounted fuse to back of his case so he could change it easily. If you do a simple bypass you lose the pico fuse (albeit oversensitive) protection.

I bypassed my current pioneer after having some noise issues. I have had noise issues with almost every Premier HU I ever had. Glad to know what it is now. The noise cause by the HU improved dramatically after I bypassed. Those pico fuses are really small though. You can also ground your shields as mentioned earlier and this will get rid of about 90% of the noise in most cases.

I have the service manual for the f90bt/f900bt if anyone wants it.


----------



## dch828

chad said:


> now we are getting somewhere!
> 
> I run BALANCED in my car and still had to avoid the wiring harness


Chad, what are you using to go balanced in your car? I'm trying to figure out the least complicated/most cost-effective way to implement it. I'm running Pioneer HU to audison(maybe try MS-8) then to amps. I'm not worried between the processor and amps because they are within a foot of each other. I have an 8-10 ft run from the HU to the processor though.


----------



## LipschitzWrath

nsaspook said:


> How old is the battery? Sometimes the whine is from excess ripple because of poor battery filtering due to high DCR from age or a failing alternator struggling to keep it charged.


The battery is a new Optima Red Top that is less than 4 months old. I replaced it when I did a big 3 upgrade.

The alternator could be bad. I've noticed that my Jeep always seems to have low voltage. After I did the big three, I am still only seeing like 12.4 volts throughout the Jeep. Compare that to my '08, when I am regularly seeing 13.8 volts. I'll have it checked. I wanted to upgrade to a bigger one anyways.


However, I am now fairly certain that the source of the noise is the left amp. I ran new wiring to my sound bar speakers and the whine was still present. I then ran the new wiring over to the OTHER amplifier and the noise was gone. This may be my fault. You see, I accidently hooked up the outputs of the head unit to the outputs of that amp (long story, sound bar speaker wires are EXACT same color and wire gauge as outputs from the head unit). So now, I am pretty sure that the amp is bad. However, when I disconnect the RCA's from the amp, the noise goes away. WTF?

Is there anyway to test the amp and determine if it is screwed up?


----------



## dma001

I managed to fix my FH-P8000BT; I'm still stunned that it actually worked, but I'm not complaining. 

I tried to post some pix I took of the fuse location, but my post was deleted - I'm not sure why. 

Anyway, thanks for the info, guys - you saved me about 300 bucks


----------



## elimenohpee

Just registered so I can reply to this awesome thread!

I have the 980bt, not the 880prs like most of you have. I did have the 880prs before I got this unit, but I never had a problem with alternator whine. But I was troubleshooting a fault in my wiring, and started swapping the rcas with the unit on, which I now realize is a big mistake with pioneers (and probably all units). I then started getting a horendous whine that changed when any electrical item was powered (windshield wipers, windows, headlights, reving the engine, ect). I found this thread when researching online, and decided to open the unit up and see if it was infact the pico fuses. 

Long story short, it was the fuse. There is only 1 pico fuse on the 980bt model I have (I have no idea when it was manufactured and whether there are different rev's of this model, but mine only has 1 pico fuse). The location is near the top right hand corner of the pcb right next the rca connects (if the front of the deck is facing you). It is in a harder to reach location than the 880 for sure; I had trouble reaching it with my solder gun, but was able to get it. I just placed a bit of solder over the fuse to bridge a connection. I would say be careful if you are trying to attempt this, these pico fuses are extremely tiny, at least in my 980bt. I've soldered 0462 resistors at work which are as big as a flea, and they are a complete pain, and this was on par with that. Plus if you don't have a good soldering iron that is able get very hot like I do, you can detatch the fuse from the pcb and then you are screwed. I was able to get it back on the pad, but it was very stressful.

But it works perfectly now, and aside from the 30 minutes of "omg what am I doing I'm so going to void my warranty" I got it working and am really very satisfied. I would say do it so you can be proud of yourself


----------



## Mark the Bold

Hello All,

Been lurking here. Have had an 880prs installed and working for 3 years now. Lately I have noticed a slight low level grumbling on the sub channel that correlates to engine RPM. Don't know if its alternator whine as I have never experienced it on my installs but sure it is. Havent touched anything although I might have unplugged the sub line rca's once (although truck was off at the time). 

Anyway, before I rip everything apart to see if its this Pico fuse. For those who had this whine / fuse issue did you have alternator noise on ALL your RCA preouts. I only get this noise on my sub channel, my front & rear RCA lines are unaffected. The reason I ask is whether to think the amp is the culprit. Please and thank you.


----------



## Horsemanwill

if it was teh pico fuse i think it's all the outputs as the fuse is in side the deck. i'd check the amp first make sure you have the power off when you take the amp out as doing while it's on is waht makes the pico go out.


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## illnastyimpreza

is there a walkthrough for the headunit disasembly? I started to take it apart, but dont wanna break anything...


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## illnastyimpreza

bump for headunit board disasembly walkthrough???


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## kyheng

What you want to do with it?


----------



## illnastyimpreza

kyheng said:


> What you want to do with it?


I started disassemly in order to investigate a possible blown pico fuse. But it started getting hairy, those screws are SO tiny ! I don't want to break my headunit....

anyone take one apart before? is there a walkthrough available?

If not, I'll just have to go for it !


----------



## kyheng

Well, you need a good philips screw driver for start... Then :
1. remove the screws following the triangle markings to open up the whole casing.
2. remove the screws for the CD drive unit
3. try search the bloody pico fuse near to the RCA pre-outs

This is what I did for my DEX-P9 and the DEQ-P9.....


----------



## illnastyimpreza

kyheng said:


> Well, you need a good philips screw driver for start... Then :
> 1. remove the screws following the triangle markings to open up the whole casing.
> 2. remove the screws for the CD drive unit
> 3. try search the bloody pico fuse near to the RCA pre-outs
> 
> This is what I did for my DEX-P9 and the DEQ-P9.....


cool I'll check it out today, I gotta install some PPI 365 s today in my new civic, (the stock speakers are SOOOO bad !) And I'll see if I have time to investigate my old Pioneer headunit when I'm done...


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## branscoset

Pioneer Deh p5100ub

Hot swapped RCA's
Alternator whine...
Replaced walmart rca cable with xtra low noise shielded monster cables.
Tested with ground loop isolator.
Grounded RCA outputs on the back of the head unit with copper wire, to the head unit chassis.
Grounded the "head unit ground wire" all the way in the trunk at same location as amp ground.
No luck still noise.
Tried running RCA wires over the carpet, then on the outside of the vehicle. No luck. Whine does not increase with volume control, nor does it increase or decrease when moving the RCA's around while care running.
I have the head unit taken apart, and searched for hours (head hurts from looking so hard) for the pico fuse that was assumed to be blown. Cant find.
Contacted pioneer but since my warranty expired 1 month ago (1 freakin month!!!) they wont touch it...at all.. not even for $$.
Audio stores in town wont touch it, and offer absolutely no suggestions, but are glad to sell me a new head unit!
hahahaha


HELP PLZ

I am currently driving around with four 6x9s two 12 custom competition subs, and a 5 channel 1600w amp, but no tunes to play through them!!

AHHHH!!


----------



## chad

Did grounding the RCA at the headunit make ANY difference? You will need to ground them all, or at least in pairs for different amps.


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## trojan fan

Clearing up signal noise can be a real PITA...good luck and stay patient


----------



## branscoset

chad said:


> Did grounding the RCA at the headunit make ANY difference? You will need to ground them all, or at least in pairs for different amps.


Chad
I grounded all of the RCA's with one continuous wrap of bare copper. grounded on both sides of the head unit using two existing screws. 

This did nothing that I could tell, no change. 

The only thing I have tried that changed anything was the ground loop isolater at the amp. That changed the whine to a lower sound, and more hiss that was not present with out it.

BTW I only have one 5-channel amp.


----------



## chad

and this sound was not there before the hot-swap?


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## branscoset

chad said:


> and this sound was not there before the hot-swap?


No, but good question. 
Adding on that

my sub was the only thing powered by my amp at that time.
my 6x9 speakers and dash speakers were being powered by the head unit.

There for I was not utilizing the front and rear rca outs on my unit. Only the sub output was in use. I have heard and assume that subwoofers cannot recreate the high frequency whine of my alternator. Or at least I have never ever heard it. My subs have always sounded great, no static, under powered, custom 12s etc. My 6x9 sounds great as well, when powered by the amp (with the car off of course).


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## chad

so you added a component (amplifier) then came into issues?

This may not be a pico fuse but rather different grounding schemes of the RCA shield between the 2 different amplifiers... 

If indeed you added an amplifier.


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## goodstuff

Alt noise can come through the sub. How is eveything grounded? Sounds crazy, try another rca cable besides the monster. Some rca's have an unterminated shield which will act like an antenna and pull in noise.


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## trojan fan

do you know the correct way to track down signal noise?.....have you been able to isolate exactly where or what(component) is causing it


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## trojan fan

I can help you track down where it's coming from, but eliminating it is the real job


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## madmaxz

im having a hissing sound with a pioneer 3300bt from all my speakers that gets louder with volume. if i pause a track from my mp3 player and turn the volume up on the HU it progressively gets worse as volume increases but its almost not noticable below volume 24-25 out of 40. it gets the worst above 30. amp gain has nothing to do with it i can turn the gain all the way down on all my rockford power series amps and the noise is still there at the same levels. ive tried regrounded the headunit to 3 different spots. nothing and ran a dedicated 12v from the battery. ground the rca's on back of the hu.

does this sound like a blown cap or pico?


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## chad

it sounds like your amplifier gain is WAY too high.


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## madmaxz

I can turn it to 0 and have the same noise level


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## sqshoestring

A fast way to check the pico/HU is pull the RCA off your amp (car and system off). Take a DMM and check the ohms on the shield to ground. It should be 0 or close to it. Touch the meter leads together and see what full short reads it should be close to that.

Best I know the safest way is to have everything hooked up and well grounded, and off, then connect the RCA. If your amp holds a charge on the RCA then its screwed up. The real problem is when an amp does not have ground some amps can ground via the RCA shield and blow the pico. It depends on the amp they are not all the same. If you are being super anal, simply test the voltage on the amp RCA shields before you plug the RCA in, there should not be any, thus no current to trash the HU.

Madmaxz- maybe try a different mp3 player or input to see if its that.


----------



## branscoset

Chad, I have not added an amp. same amp i have been using for months. Only difference is I started using the other 4 channels to power 6x9s, as opposed to previously only uses the amp to power my subs.

I am almost ready to break down a buy a new head unit.

Can you guys suggest the best size wire and location to ground my deck. I currently have it grounded in the trunk using an old speaker wire that was already ran. Some one told me I should ground my deck in the trunk at the same location as the amp.. I am reluctant to do this.

I have the gains on my amp barely turned up right now, like they arent even on. I cant hear the 6x9s at all, and my indash 4x6s that are powered by my headunit still are over powering my 6x9s because the gains are so low. 

BUT I STILL HAVE RIDICULOUS ALTERNATOR WHINE ::mean:

re-cap
upgraded rcas to zero noise 4 chan monster cable
grounded(soldered) each rca output(3 pairs) on the back of my head unit
head unit grounded in the trunk
amp has proper grounding
took my head unit apart couldnt find pico fuse so I put it back together
ran rca down opposite side of car as power wire

also
I notice when I unplug just 1 rca wire from my amp(out of 4 chan wire)
the noise goes away


----------



## sqshoestring

Swap the RCA around on the amp (to wrong channels) and see if the noise travels with an RCA or if it stays with one RCA terminal on the amp. Don't run a bass signal into a tweeter if you don't have a passive xover on it of course, etc., if you have to swap high/low RCA. You could have a bad solder on the RCA plug for example, you could try gently moving it around to check or loosen the screw in it a little and move it, etc. Or you can check ohms on all the RCA shields on the amp and the RCA, while not connected to each other. If one on the amp or HU are different from others that could show the problem. HU should be near 0 and some but not all amps are 1K ohm to ground on shields some different. I don't think I have ever grounded a HU in the trunk I do it to the dash/car structure nearby, but others have. Most cars have a big ground to the engine for the starter, then a ground cable to the firewall behind the engine as well as a body to battery ground. So if you ground to metal behind the dash it should be a good ground.


----------



## cruzinbill

madmaxz said:


> I can turn it to 0 and have the same noise level


did you ever figure this out? ive had the same problem a while, at first i thought it was the routing of my rca's but now im sure its not. I have the exact problem it always sounds like the gain is way to high even when its all the way down.


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## chad

On most headunits when you turnt he volume to zero it literally mutes the outputs electrically (well electronically) with FETs.. Unfortunately this happens before the pico fuse.

I'm wondering if Fryanear has not caught on and has stopped using this protection scheme. This thread is pretty old so hopefully they have, don't hear about it as much any more.


----------



## NZ-EzyE

First post, signed up to express my gratitude.

Developed electrical interference yesterday out of nowhere (alternator whine, buzzing, sub popping when changing sources), and managed to narrow it down to the head unit (DEH3000IB) today by swapping in a new source. 

Googled the problem, found another post that lead me to this thread and decided to disassemble the unit to see if it might be the same issue. Put the multimeter across the only fuse we could find on the board, and got no reading, so we removed the fuse and replaced it with a ball of solder (cowboys, ho!), reassembled, tested, and the issue is gone.

Thanks for the help guys, you've saved me buying a new head unit.


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## OGJordan

If it means anything to anyone, I just changed out an Alpine 9833 that I ALWAYS had a slight whine from for 3 vehicles for a Pioneer 80prs and the whine is GONE. I tried everything from moving grounds to ground loop isolators to multiple different RCA and RCA routes and never could fix it.


----------



## mfarlow

First off, thanks to everyone for posting a solution to this problem. I plan on replacing the pico fuse with a resister next weekend.

Was there ever a clear guide to installing the head unit in a way that would guarantee not to blow the pico fuse? I've been reading about this across many different sites, and there seems to be contradicting information as to what should be hooked up first.

What makes sense to me is to connect all the grounds first prior to connecting the RCA's at the head unit. Does that sound correct?


----------



## kyheng

Guarantee? Can, either you buy the DEX-P99, DEX-P9 combo or ODR sure won't have this problem.....


----------



## hirino

guys, i want to start off saying this thread has some great info . i just bought a used pioneer 880 prs and it had the blown pico fuse so i had my local shop do the repair and the noise got alot better but i still have a hiss/ whine alomost like static comming thru my highs and it does seem to be like alternator whine but is present even with the car off it starts at 0 volume and gets higher up untill i get masked by music . also i get a thump from my mono amp if i turn volumeoff and on . the shop pretty much gave up and said that they have no clue and need to start replacing parts untill they figure it out . i did try to ground the chassis but is still present and my old kenwood did not have any of these issues . i tried turning the gain down on the amp all the way and the noise is still present. any info would be much appreciated.


----------



## hirino

anyone one reply to this thread ?


----------



## Horsemanwill

turn off the hu. go to the amp and remove the rca's make sure they don't touch anything. turn on the hu. is the noise still there?


----------



## hirino

Horsemanwill said:


> turn off the hu. go to the amp and remove the rca's make sure they don't touch anything. turn on the hu. is the noise still there?


the noise goes away when rcas are unplugged.


----------



## Horsemanwill

turn off the hu. put the rca's back in the amp. remove the hu from the dash area. make sure all cables are still attatched. turn the hu on. is the noise still there?

start a new thread so as not to clutter this one.


----------



## hirino

yes noise is present . also i did start a new thread
http://www.diymobileaudio.com/forum...o-discussion/139187-pioneer-880-prs-help.html


----------



## blaket02

I am having some bad noise issues. I have narrowed it down to my head unit. It is an avic x930-bt. I have it apart but can't locate any thing that has been described in this thread. I have a board which the harness for the vehicle attaches and also a board for the pre-outs. I have the schematics but cannot figure them out. Can anyone help?


----------



## sqshoestring

The outside of the preouts RCA should be grounded by the HU as well as the outside case. If not that is your issue. Check those first. You can wire the case or rca shields to ground at the HU to test (not the inside of the rca, don't short them to ground most wrap a wire around the plug on outside to check them) What can happen is an amp loses ground or have some issue and tries to ground through the RCA, which then blows the tiny trace or fuse in the HU. This has always been an issue and depends on how the amp is built if it can do this, and of course how good your wiring is. Some Pioneer have a tiny fuse in them that blows easily. Mine is fine for years now, but no amp problems and they are well grounded.


----------



## toomtoomvroom

Hi all, just wanted to share with everyone my experience. 

H/U: Premier 880PRS
Incident: Hot Swapping RCAS. 
Symptom: 
-Significant whine/ noise coming from only one channel Front Passenger
- Also can hear a loud pop when turning volume between 0 and 1
- Noise/ Whine increases in pitch as RPMs go up and down
- Noise only exists when I plug in my front pair RCA's into the Amp which is a PPI 6600.6

I'm currently able to run the setup with just the 880PRS rear rca out signals plugged into the Amp's Front signal inputs and the Amp has a combine feature allowing the entire system to be powered by only the headunit's rear signal outputs. I hope I'm making some sort of sense here. There is occasionally an electrical whine whose pitch is consistent with the engine's RPM. Sometimes it's there and sometimes it isn't. Funny thing is only time I've ever been able to consistently prevent the whine and allow the whine.. is if I pull out of the garage, the whine starts. if I back into the garage, the whine goes away. lol
I was able to pull out, back in, pull out, back in, and it was a very reliable way of causing and preventing the noise. 

Each one of the red squares are where we placed the tips of the DMM to measure resistance
Story: 








So we took apart the H/U and used a DMM to measure the two ends of the FU351 Pico Fuse and it read a full 1. Therefore, we understood this to show that there was an open connection and a blown fuse. We then dropped a big glob of solder over the FU351 like most have said in this thread hoping that it would work. However, the solder glob didn't fix the problem. 









We then noticed on the back side of the board, there are resistors ( I think) that are labeled to each corresponding channel of the six. My buddy decided to use a DMM and measure the two points connecting to the resistor. 









Interesting part -- Each one of the black resistors labeled 390 read a 040 on the DMM. except one. --- FR1--- labeled R352 my front passenger channel. 
FR1 on the DMM reads a full 1









Hypothesis: I can't remember what I hit when I was hot swapping the RCA's, but whatever it was, had enough juice to blow my Pico Fuse and the resistor for that one specific RCA cable that touched something hot.

My question now is how best to approach this? Should we solder glob the channel with the blown resistor too? My buddy was reading that these attenuate the signal, effectively manipulating the gain and noise. He says it's to prevent too much noise. Or should we solder in a 390 ohm resistor in the shape of a staple ontop of the blown resistor that's in place. 

Goals:
My goal in all of this is to get this H/U back into working order 100% I really enjoy this unit and hope that I can fix it giving me many more years of enjoyment. 

Neither of us are engineers or car audio professionals. Just guys being guys and breaking their stuff... and trying to learn something along the way. 
Thanks advance!
I have more high res photos of the board disassembled if that will help anybody else in the future, and I'm sure I may have left a few things out of here. I did however do my best to explain the symptoms and steps taken. 

I've been driving around with the current rear output signal to amp input signal as a work around until I was able to research/ find this thread/ decide what to do/ and get to this point.


----------



## Hanatsu

Bypassing components in a circuit can lead to unpredictable results. Can't you replace the SMD resistor? Shouldn't cost much.

Tapaaatalk!!


----------



## toomtoomvroom

Does anyone know how to find the part number for the "390" smd resistor I'm trying to replace?

I think the 390 stands for a 39ohm resistor. Which is consistent with why the DMM read 40. 

Could I pick up a 39 ohm resistor from fry's and solder that ontop of R352. Would it make a difference if we removed the old blown resistor as well? 

Thanks again


----------



## Hanatsu

It's a 39 ohm resistor. If it's open, it doesn't matter, just solder it on top.

SMD resistor code calculator


----------



## toomtoomvroom

welp... we weren't able to find a 39ohm resistor, so we soldered on a 33 ohm resistor hoping that it would help, which it did. 

The blaring alternator whine out of the front passenger channel is significantly reduced. 

I still however get a pop when I run the volume down to 0 and back up to one. 

anyone have any further ideas? 

here's our solder job :-D i'm very happy with the connection, it took four hands but it's got good strength to it


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## MKnigghtMD

Should the head unit be grounded in addition to using the ground wire in the harness?


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