"William Sommerwerck" wrote in message
. ..
This isn't criticism (no way), just a question...

Do you think this was a rational repair, or was it a matter of luck?

I'd like to hear a bit about how you finally decided (or discovered) that
this cap was the problem.


Very much a rational repair. I pride myself on my troubleshooting skills.

Upon observing what happened as I kicked the filters/tone controls in and
out, it was easy to surmise that it had to be either the tone control
circuit or the first stage of the power amp, and that it had to be a cap.

Digging into the schematic I found that there was only one active component
per channel in the tone control circuit, and that only one cap could cause
the same problem with either of the two switches in the positions that
caused the problem.