I have that Kawai analog synth that had it's nicd battery leaking... leaving green acid over a one inch square area over the main PCB.
It at first just played it's own notes automatically and randomly.
After I cleaned the area it stopped playing automatically and started to somtimes play double notes when you hit only one key... I had it replaced a few parts where the defective area is including the battery itself, and validating all connections are still conducting.
The problem is that after I replaced 3 electrolytes, it's dial wheel has stopped to respond ! of course I tried to reverse the operation but no success. There is no sign of polarity for those caps on the board but I double and triple checked that they are put correctly.
Now, I found sometihing strange -
there is a short between a transistor leg, BUT it doesn't come from the tranny (it's ok) and it is there ONLY when the synth is powered up, and for a few seconds after I power it off.
The same occurs between two other spots, of two components that are placed near each other.
Another sympthom that I don't know if is normal, is the main chip (made by intel at '82) and the EPROM chip that are getting a little warm when the synth is ON.
Do you have any clue what type of problem is causing this ??
What shuold I check ??
Thanks all !!