Touched up solder joints, pulled the trimmer and it tested fine again, so I'm going to keep digging I guess.
Dumb question, but it could be the output transistors doing that correct? I would only have to worry about silicon breaking down I think and that's the only thing I haven't replaced.trimmer might be breaking down under load . or something else is .
TR508what voltages are at the outputs ? BCE
Across R519.where are you measuring the bias ? in theory there shouldn't be any idle current at those outputs .
As I was moving the board one lead of R520 broke so guess I'll be getting back to you on that tomorrow I guess. That was just lovely timing on the resistors part :/for insanity reasons read voltage across r520
And that wasn't it. Not that I'm surprised. Next order I might just order all new transistors again, and clean the board with rubbing alcohol once more.
This was five years ago. I don’t even remember what I did this weekend.Did you manage to find out the issue?