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View Full Version : Pioneer RCA Preamp outs dead, repairable?



scoob8000
11-05-2008, 08:59 AM
The preouts on my 3900MP in my fiances' car just died. I'm getting about 1-2mv on all 6 channels, so I'm assuming it's something internal.

Anyone ever fix dead preamp outputs? Sending it out for repair will probably cost more then the unit is worth. And unfortunately I did not buy it from an authorized retailer, so no warranty. :/

chevy_man
11-16-2008, 09:58 PM
If it's worth it to you, take it to a small electronics shop and get it fixed locally.

OR, buy a schematic and trouble shoot it yourself, but you'd want an oscilloscope and they're not cheap.

IIRC, the 3900 is a sub $200 unit. Just get a new deck IMO.

scoob8000
11-17-2008, 11:04 PM
If it's worth it to you, take it to a small electronics shop and get it fixed locally.

OR, buy a schematic and trouble shoot it yourself, but you'd want an oscilloscope and they're not cheap.

IIRC, the 3900 is a sub $200 unit. Just get a new deck IMO.

Just saw a post (actually I think you may of replied to it) about a blown pico fuse in some pioneers. I'm beginning to wonder if thats the case.

I'm 99% sure it quit working when I installed a new amp, and like a bonehead plugged in the RCA's with everything on. (Done this many times before, never gave it much thought)..

scoob8000
11-19-2008, 07:24 PM
Tore it apart and finally after about 30 minutes of squinting and probing I found the problem!

First, this board is different then other Pioneers I've seen pics of. Most of the components are on the bottom side of the PCB, requiring PCB removal from the chassis.

Found the pico and probed it, good continuity.

Then I started probing around it and found an intermittent connection. The PCB trace between the shield connection and the pico fuse is actually lifting!


No way to glue down that tiny piece, so I put a blob of solder between the fuse output and the shield.

That would explain my low volume that would change as I wiggled the RCA's on the HU.

Going out to reinstall the deck in a few minutes. Will post back!


http://post.mach-five.com/posted/1/Car_Stuff/pioneerpico_thumb.jpg
(http://post.mach-five.com/posted/1/Car_Stuff/pioneerpico.jpg)

scoob8000
11-19-2008, 08:34 PM
****! Still no luck!

Must be more damage to the PCB. As much as I've loved Pioneer HU's in the past, I think this one is my last...