I have a TR707 tha tI have not used in 10 years. Dust free. powers up
and all displays work but no sound. tried everything even tried to
trigger the voices via MIDI from my keyboard and nothing. volume
sliders don't even hiss when moved. total silence. all other
functions seem to be OK, it enters all modes. I made sure it was on
internal clock, tried individual outputs, NOTHING. any suggestions