j.harv
@#$%
Are the record amps on individual cards, one per track?
When you did your swap what cards did you swap?
Some of what you describe sounds like relay issues to me.
And on your power supply board repairs, based on what I saw of the battery leakage damage, I'd strongly consider bypassing the effected solder traces and adding jumper wires instead. Battery acid will eat foil.
Okay...scrap my last post. I think it has to do with the rc/pb cards. Sweetbeats, the cards have 2 tracks per card like a 388. I just finished swapping cards again and the problem did move. So my track 11/12 and 7/8 card seems to have a problem. I pulled them out and looked them over for any visaul problems, but I can't see anything. What I did do though is when I recorded something on track 11 and played it back, I gently wiggled the card and got a audible distorted swoosh kind of sound on track 11 when listening back. Even though no recorded sound made it to that track. Same thing happens with track 7. I'm gonna flip the machine up and see if I can get a glimps of the mother board under neath and see if any of the card connector solder points are bad in any way.
As for the power supply, I was thinking of putting some jumpers on, but the "roadmap" of traces are hard to follow because of the green coating that flaked off. So I don't want to risk connecting any points together in the wrong way.