I was able to remove the panel that holds the two amp sections, flipped over and started pulling the transistors to check. Under that one suspect power panel it has 8 total transistors, group of 4 on two sides. 3) SJ6357D and 1) SJ6344. So far I’ve tested “bad” one of the 6357s on each side, but haven’t gotten to the 6344s yet…am I getting somewhere?

If you checked the transistors with an ohm meter properly while removed from the circuit, then they are probably bad.
So yes, you are getting somewhere. Its very common for failed power amps to have bad output transistors.

 

Still here and no further movement—more home stuff and wife-requests getting in the way…also, calls to Peavey Parts have been no help for over a week…seems their “system” has been down and they’re unable to look things up. I haven’t checked back for last couple days…maybe Monday.

 

Still here and no further movement—more home stuff and wife-requests getting in the way…also, calls to Peavey Parts have been no help for over a week…seems their “system” has been down and they’re unable to look things up. I haven’t checked back for last couple days…maybe Monday.

Don’t give up, you’ll get it fixed.

 

Don’t give up, you’ll get it fixed.

I went ahead and placed an order for several off eBay yesterday…

 

Check the transformer primary resistance. If it is almost a short circuit, replace the transformer.

for reference, what sort of value for primary resistance would you expect across a mains transformer primary ?

 

UPDATE: SOLVED.
Many thanks, again, to you fine folks. I finally got around to digging back in and replaced two of the 8 transistors (in one channel). Also I had bought one of those cheapie transistor checkers which allowed me to tell which ones didn’t look like the others. Hooked up my new dim bulb tester (can’t believe I never got around to making one before this) powered up. Tester went quickly dim and I heard that old familiar “thump” in the speakers. Tested channels with a mic and all is well now. Well…almost…while doing the mic test I’d run across a channel that seemed dirty or scratch with low gain, so I’d jack up the level. Then I’d get a loud low-end “oscillation” of sorts that wouldn’t change with any control input. I’d power off and power up again and it was fine. Seems to me that if the channel was “weak” then this would happen with raising the channel level fader, until the channel was exercised a bit…

 

Dirty or scratchy is a call for tuner cleaner. I recently repaired an expensive tape deck with Tuner Cleaner. I used a whole nickel's worth.