Moog Music Forum

the Opus 3 I'm trying to repair's String section and Chorus doesn't make sound, I've tested all relevant chips with a Multimeter and they all seem to be ok, I read in another post to maybe test the mix slider with an audio probe and I will but if that's not the problem, where else should I look? Wiring path?

you can always check the solder under the connectors, I remember seeing an opus once which was missing strings because of a cold solder there. Otherwise, as usual it's a difficult to troubleshoot anything over the internet. Always best to take it to someone who can look at it if you are stuck.

You get the twelve note from the top octave divider? You can use a probe and listen for the notes.
If not, check the top oscillator (you need a scope for this).
If this does not help, check the inputs and outputs of the octave divider chips (you can hear the signal with a probe).
But I don't think, that all octave dividers gone bad at the same time.