I have a Korg SQ-10 sequencer here that has been playing up. It was acting up a while ago but after I looked at it and then put it back together, it seemed OK for a while. That led me to suspect a dodgy connection or a dry joint... but I'm now discounting that as I have been pressing on different parts of the circuit and moving connectors and it stays faulty. So I am assuming component failure.
The symptoms are a wavering and very unsteady/un-solid pitches on steps 2 > 12 on all three channels - A, B and C.
Strangely though, step one is solid (on all channels)..! I have examined the schematic and there does seem to be a step that has a unique path - but that seems to be step 12, not 1..!
To date I have changed IC H (4066) and also IC D (LM324N) but all symptoms stay the same.
I am fast running out of ideas... but think that surely the fact that step 1 is solid, is pointing somewhere...!?
Cheers,
TOM