thanks; very good ideas; was not successful in bypassing the switch; will keep trying, however, I think a big clue is that, after getting it to start, unplugging and plugging the power supply does not restart it; I think that would eliminate the switch. someone somewhere suggested APO could be invol...

AC

when it runs, there is 10VDC all over the board

it's fine once it starts but that's not often or predictable

Have you got an idea?

I have a clean CZ-101 apart on my bench. Power switch has been sprayed and synth is fine when power actually turns on, which is about once every 30 cycles of the power switch. Relay seems operational when power is on. Power on circuit schematic seems complicated. http://www.burnkit2600.com/manuals/C...