Strange x0xb0x

[mmm]

Please check again at pin 1 of IC15B (I misread the schematic).

The 12V on pin 8 are not ok. Please check very carefully if there is possibly some solder bridge between pin 9 and pin 8 (alternatively you can check with a multimeter if there is a short).

[Chris72160]

Hello,

pin1 and pin2 have both 5,32v.

pin9 and pin8 are not physically connected together.

What do you mean with that: "I misread the schematic"

Tomorrow i can make more pics with my oscilloscope.

Greetz Chris

[mmm]

Hello,

pin1 and pin2 have both 5,32v.

Yes, but we need the AC voltage on top of this; so you need to check this with the oscilloscope.

What do you mean with that: "I misread the schematic"

I didn't catch that the two connections to pin 1 and 2 of IC15B were crossed. Pin 1 has DC bias and signal, pin 2 just DC bias.

[Chris72160]

So, now here my probes..

Greetz Chris

[mmm]

It's difficult to say if there is something happening.

It probably would be best to leave the horizontal resolution of the scope at 5ms (like for the measurements at the waveform switch). Please set cutoff to max and resonance to min. Check both sides of R121. One side should have a strong signal, the other side a much weaker version.

Also check with the multimeter what is happening at pin4 of IC15B when playing a note.

I'll probably not be able to check in here before Monday evening.

[Chris72160]

Hello,

on pin4 of IC15B (BA6110) i have 11.78v when playing a note.

Last photo shows trigger on pin4.

Greetz Chris

Edit: Problem solved!!! I soldered a new BA6110. A bad BA6110 was the reason. Thanks for your enormous patience, MMM!!