# Pioneer DEH-80PRS cutting out under vibration/high volume



## mlab8 (Oct 1, 2016)

I've done a lot of newbie testing , so this could be quick to diagnose. 

Pioneer DEH-80PRS head unit starts cutting out or skipping continually and only stops if I keep the volume pretty low. Any attempt to raise volume at med-high levels makes the sound cut out repeatedly again. 

Happens with radio as well (not CD skipping), only at higher volumes. 
Happens with engine on or off, only at lower volumes with engine on (higher voltage read on screen).
Not running an amp, just HU and 4 speakers.
Does not happen with other Pioneer head unit used for testing, DEH-X9500BHS. So nothing wrong with wiring, speakers, etc. It's the HU.

HU plugged in and sitting on passengers seat, starts cutting out when I tap on the top cover with my fingers, near the heat sink or antenna, mostly. So, I know road vibration is what starts it.

Lower the volume, stops cutting out, raise the volume, cuts out again. Keeps doing this forever. 

Tap on it again a few times and it fixes itself. I can raise volume to max levels again.

Tap again, starts skipping / cutting out again. Tap some more, fixes itself, and so on...

None of this happens with other head unit (DEH-X9500BHS).

Very willing to open the thing up and solder or replace parts. Just need to know what to look for.

Please help!


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## StateOfZen (Nov 23, 2016)

Did you ever figure out what was the problem?

Mine started acting up and the same way.It only had a few months.


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## StateOfZen (Nov 23, 2016)

Ok Thanks, I am still under warranty ,was just wondering if it was a bad ground or something etc.Gonna pull it and put my old stereo back in ,and test it. It was playing intermittently from all sources , now it plays on the screen but no sound at all.


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## lynchknot (Sep 27, 2014)

I've seen similar behavior from other decks with a dirty/dusty volume pot.


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## StateOfZen (Nov 23, 2016)

Really? Will try spraying the faceplate with some electronic cleaner around the Rotary / volume knob


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## MikeS (May 23, 2015)

you can start 80prs by pressing the tab under faceplate and run it without faceplate by wedging the button down.. set the volume before taking out the faceplate.

One thing to check is that all the pins in the harness connector to deck are still locked in place. If something is not connecting properly it might cause strange things.

If you have warranty do not spray it with anything.


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## StateOfZen (Nov 23, 2016)

God Point , I will look at it tomorrow thanks.


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## StateOfZen (Nov 23, 2016)

I found out what the problem was , the in line 100a fuse had melted and was powering the amps intermittently. I looked and all the amps lights were on so i didn't suspect the power to the amps,but a little further digging i found the inbound side of the fuse and holder had melted!
So in a way i am glad it was not the DEH-80.


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## gijoe (Mar 25, 2008)

You should be even more glad your car didn't catch on fire. If I were you, I would double check all of the wiring!


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## Jscoyne2 (Oct 29, 2014)

StateOfZen said:


> I found out what the problem was , the in line 100a fuse had melted and was powering the amps intermittently. I looked and all the amps lights were on so i didn't suspect the power to the amps,but a little further digging i found the inbound side of the fuse and holder had melted!
> So in a way i am glad it was not the DEH-80.


When a fuse melts like that. Its usually because either the positive wire shorts to the body. Such as the plastic covering over the wire wearing away till the positive touched the body of the car.

Or

Its because the ground isnt good enough and massive amount of resistance builds up

Sent from my SGH-T999 using Tapatalk


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## StateOfZen (Nov 23, 2016)

gijoe said:


> You should be even more glad your car didn't catch on fire. If I were you, I would double check all of the wiring!


Yea, first thing i thought , all the amps and fuses seem fine ,as well as the stereo , got lucky overall, didn't smell anything , the amps are in the back under the floor on a pice of MDF, and the battery and the wiring are under them with the dough nut spare 



Jscoyne2 said:


> When a fuse melts like that. Its usually because either the positive wire shorts to the body. Such as the plastic covering over the wire wearing away till the positive touched the body of the car.
> 
> Or
> 
> ...


Thanks , it is one of the two , going to look into all the positive wiring again and redo the ground with something thicker than the stock wire they have to the frame.


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## MikeS (May 23, 2015)

That's why I have quite a small fuse (60A) on main wire, hopefully prevents burns like that. Spare in glovebox but haven't blown one yet.


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