[sdiy] Broken SH-101 - ideas wanted...

[Florian Anwander]

Hello,

I have here a Roland SH-101, which does not make sound.

The CPU starts the boot, but does not reach the testmode 
(Load+Keytranspose while power on). When I switch the synth on, first 
the Keytranspose LED is lit, and a second later the Hold LED is lit also 
- both LEDs stay on and cannot be changed. And nothing further happens.

Also the CEM3340 does not oscillate (checked with scope at the outputs 
of the chip).
The Noise works ok on the mainboard (checked with scope and audio at the 
buffering OpAmp), but does not reach the VCF!
VCF, LFO, ADSR work fine (checked with full resonance and external CV 
and Gate).

All supply voltages read correct values.

Any suggestions?


Best regards Florian