# EFF YOU PICO FUSE!!!



## Mooble (Oct 21, 2007)

So now I know what it sounds like to blow your pico fuse on an 880PRS. It's the most god awful whine you're ever heard. It's like alternator whine x 10. Not only do you hear alternator whine, but you even hear the transport spooling up. It's unreal!

I blew the damn thing trying to install a HU cap. While I was disconnecting everything I also must have grounded something because there was a horrible pop. I nearly **** myself because one tweeter wasn't working so I thought I had either blown a tweeter or one channel of my amp. Fortunately I later discovered that an RCA had come unplugged. *relief*

Okay, so back to the pico fuse. Did I go out and buy a resistor? No. Did I buy a precision soldering iron to fit a new fuse in the tiny workspace? No. 

So how did I solve the problem? Simple. I dropped a big bead of solder on top of the fuse that connected both leads. Voila! Dead quiet again. It was a PITA trying to get the solder to sit on top of the fuse, but with enough tries, it worked. It's an ugly ass repair that's for damn sure, but it's fixed.

This was the project I was working on. I don't know if I'll bother with the HU cap anymore. I'm a little gun shy at the moment.

















Crazy-ass rats nest!


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## buchaja (Nov 10, 2007)

That's the DIY spirit! Big ol' glob of solder FTW!


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## Austin (Mar 12, 2009)

What was the cap for?


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## chad (Jun 30, 2005)

Oh yeah....








Wait for it.....


























Bwa, hahaha.... 

good job on the blob-job I would ahve done the same.


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## Mooble (Oct 21, 2007)

Well I tried to jump it with a tiny strand of wire but the soldered wire wouldn't stay attached. I don't think there was enough exposed lead for a good solder. Then I just said F! it and dropped a big ol' solder bead on top of the fuse itself. It's a tiny little fuse. It didn't take much solder. It's only about 1mm across.

The cap was to try to stabilize my voltage. I have an underdrive alternator pulley so at idle the voltage can swing considerably. I thought the cap might help at idle. It's probably safe to reinstall the cap since the pico fuse has been bypassed, but I'll leave that for another day.


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## Mooble (Oct 21, 2007)

.....


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## 89grand (Nov 23, 2006)

I think it's great that the reference designator is FU...lol!


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## gijoe (Mar 25, 2008)

89grand said:


> I think it's great that the reference designator is FU...lol!


I thought the same thing when I was fixing mine, I wasn't in a good enough of a mood to laugh about it then though.


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## 89grand (Nov 23, 2006)

I've had an 880, and I've had a blown pico fuse, I wasn't laughing at the time either.

It's a great deck, but Pioneer really needs to fix that ******** design.


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## t3sn4f2 (Jan 3, 2007)

Glue blob on top of the solder blob, _just in case_. You don't want that little thing bouncing around in there if something goes wrong.


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## ChrisB (Jul 3, 2008)

Mooble, did I read your sig correctly? A Clarion DPX11551 for your sub.... Say it isn't so.


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## sqshoestring (Jun 19, 2007)

One guy put wires on it, then screwed a little fuse holder on the outside with a 3A in it. I'll mod mine somehow if it pukes, but no prob so far. I modded the deck I test amps with and put a fuse holder on it, but then I thought stupid why didn't I dig out a dash light/marker light holder for one of those peanut bulbs. It would light up when it had a fault, hey that would certainly be more fun....light bulbs are great for that stuff....not so good in a car unless you could see it.


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## tinctorus (Oct 5, 2009)

So does the small capacitor on the constant power supply do anything worth while because if it does I may be interested in performing this myself


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## Mooble (Oct 21, 2007)

ChrisB said:


> Mooble, did I read your sig correctly? A Clarion DPX11551 for your sub.... Say it isn't so.


Sure did. It's a great amp and considering it retailed for $800, $200 is all the more appealing. I've never thought spending money on an "SQ" sub amp was worthwhile. It's a sub amp. Who cares as long as it makes reliable power? I used the LP only because I had nothing else. I sold the LP for $400 more than the Clarion which paid for the Ultimo. It was a toss up whether I kept the LP for my mids or the Tru. I decided the Tru was cooler. It definitely had more balls per channel than the Tru though.


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## Mooble (Oct 21, 2007)

tinctorus said:


> So does the small capacitor on the constant power supply do anything worth while because if it does I may be interested in performing this myself


There is a small one inside the HU anyway, but it's very small. I forget what the capacity is on it. The Cornell Doubilier I used was 33k uF. That should have enough reserve to level off the voltage to the HU and the SSLD6 at idle. 

In most cars it probably won't make a difference. I thought it would help in mine because my voltage ranges from 11.7 at idle to 14.7 at full power. Unless you have an underdrive pulley, your car will likely make full voltage all the time.

I'm getting brave again. I will probably reinstall the cap tomorrow and see if it helps.


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## tanakasan (Sep 8, 2007)

Mooble said:


> That's the little SOB right there. I didn't take a pic with the solder bead on top though. I was in too big a hurry to reinstall it and see if it worked.


*^^Looks just like my pic from my DIY post here on 9-07-2007, post #86 on this thread http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/13889-pioneer-rca-preout-noise-prevention-4.html. The screw is turned exactly the same, the shadow from the screw and brass standoff is exactly the same and marred on top exactly the same, the sleeve on the cap is clocked exactly the same!

I forgot to take a pic of my finished repair also!

Robert*


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## Austin (Mar 12, 2009)

^^^ wow that is weird!! Yours is more clear though  haha. But still the lighting is exactly the same..

Edit: Nvm i think it is the same pic... Haha


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## chad (Jun 30, 2005)

........


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## Mooble (Oct 21, 2007)

tanakasan said:


> *^^Looks just like my pic from my DIY post here on 9-07-2007, post #86 on this thread The screw is turned exactly the same, the shadow from the screw and brass standoff is exactly the same and marred on top exactly the same, the sleeve on the cap is clocked exactly the same!
> 
> I forgot to take a pic of my finished repair also!
> 
> Robert*


It could be your picture. I just did a google image search for "880PRS pico fuse" to show people which one I meant.

I'll remove it.


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## Oliver (Jun 25, 2007)

Why not disconnect the power first ?

Can a fuse blow with no power to it ?

Is disconnecting the power *very ... very .... time consuming*


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## Mooble (Oct 21, 2007)

Power *was* disconnected until everything was wired up. When I turned the key I heard whine, although it didn't seem as bad at first. At the same time I did this, I also wired the HU straight to the battery. It could be that when I first powered up, I got some noise from the new power line and the pico had not blown yet at that point. I was checking connections when I heard the pop and maybe that blew the pico which was when the noise really got bad.


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## tanakasan (Sep 8, 2007)

Mooble said:


> I'll remove it.


No, no biggie! Just saw it and thought [email protected], that looks familiar!

The wire wrap on the RCAs "bandaid" fixes 95%, but the Pico repair is 100%. Doing the resistor fix was a bear!

*Well done there with the solder blob!*:thumbsup:

Mine blew the same way. Power disconnected for the swapping/reconfiguring. Reconnected and rechecked everything, then when the ignition was turned, a great big pop and the most terrible noises ever!

Robert


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## M-Dub (Nov 29, 2006)

Yup! Blob o solder does the trick! I did that after I sneezed and blew the pico 
People are going to say something bad is going to happen now that your not fused. I'm still waiting.


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## tanakasan (Sep 8, 2007)

M-Dub said:


> I did that after I sneezed and blew the pico


That's all it takes!:laugh:

Robert


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## sqshoestring (Jun 19, 2007)

A bad amp ground can do it, some say powering the amp then hooking the RCA up can do it iirc. Different amps do different things with the shields.. but that is where the power needs to come from to blow it.


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## chad (Jun 30, 2005)

sqshoestring said:


> A bad amp ground can do it, some say powering the amp then hooking the RCA up can do it iirc. Different amps do different things with the shields.. but that is where the power needs to come from to blow it.


what if the RCA shield is attached to the center tap of the secondary of the power transformer...... Like most amps are.

It's still a ****ty design fryanear pushed over and continues to push over on it's customers.


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