Pioneer 939 issues

Scored a 939 not too long ago. Plugged er in. No sound, not even headphones. Lights are on, It sound like the relay clicks on and then quickly shuts off possibly. Attached are pictures of some issues I've found.

1. the power board on the underside is discolored in the upper portion, by the transistors. pics 1&2

2. same board, has ceramic caps that are "bulbous". Pic 3

3. Top center board has a yellow looped wire that is severed. pic 4
Anyone know what this wire is for?

any advice would vastly appreciated.

3. The cut wire is a factory setup / troubleshooting link, tying pin 7 (mpx out) and pin 31(mpx in) together for initial check out, then once the muting thresholds and tuner adjustments are done, that is cut, allowing the AWM-063 muting circuit board to actually function.

2. ceramic caps look like that, there may be some wax on them that "cold flowed" under the temperatures and redistributed itself.

1. sure, discolored by heat. Rebuild the power supply for long term longevity. Make sure the unit has room to breathe when running, this one bears the appearance of being "bottled up" and cooked a bit.

You have 2sa725, 2sa726 transistors in it, replace with ksa992
there are 2sc1451 transistors in the amplifier board - THEY MUST BE REPLACED with ksc3503.
There are MANY sky blue Sanyo "capsistors" - failing capacitors in it. Get them all out of there... there are lists of parts for all this.
ANY of these can be making your power amplifier section misbehave, but they are NOT limited to just the amplifier section..

Follow the list, do it once, and then enjoy it for many, many years.

Thanks Mark!

I believe this is the last 939 that was done before yours. Relist the parts list on Marks post there on here for vetting. This one was a "BASKET CASE" and it started out as a toss up whether I should rebuild it or not.
Here's the link for the thread. http://www.audiokarma.org/forums/showthread.php?t=494501

And this one about the idle current change.
http://www.audiokarma.org/forums/showthread.php?t=512271
If you don't understand something, ASK 1st, take action AFTER answers.

Thanks Larry. I read through the entire post. That looked like a bear of a project! I probably will have to find a tech for this one, as it's way beyond my scope of technical ability. I'm bound to screw up installing transistors and will just get solder all over the board.

Well I hooked the pre-out to an amplifier. Sound! The problems must lie in the power section. great.