Cutting down the detective work

I built a Shruthi way back SMR 4 board v 0.7 it which I loved. It is back after 15 months absence and although fires up and sequences there is no sound. I would be grateful for any pointers where I should be looking to solve this , the clown who had it may have put 12v centre negative through it , I don’t know. Any pointers to older troubleshooting documents would help as well.
yours appreciatively. I loved this little beast, it was my first MI build.

  • Does it receive MIDI?
  • Sound on the OSC> pin?
  • Otherwise, go through the signal chain…

Re midi, I plugged a keyboard in , and with note on , the note symbol appears very breifly on the shruthi, very dark and fades. IIRC it should be white (on blue)?. I am waiting for some breakout/breadboard cables to break the Shruthi apart before i test further for the audio signal continuity.

So if the symbol appears it’s all good, next step is checking the OSC> pin.

problem found
connectivity issues between digital and filter boards. Works fine as shown in the photo.
I shall get some new headers or perhaps ribbon cable it. Glad to have it back, it is mine again.