Vintage Synth Repair

I've got a micromoog with a problem; a note is always triggered when
the micro is on.

If I were to turn on my micro right now, it would sound a note, even
though no keys are pressed down. If I were to press a key while the
micro is on, the note sounded will change pitch to that key, but will
still sustian indefinatley after the key is released.

I've looked at the service manual, and so far the only thing I have
done is clean the buss bar and j-wires with rubbing alcohol and
q-tips. That did not do anything.

This is really getting frustrating, because this is my second
micromoog that has had this problem. My first one I sold (to someone
who knew the moog had issues) had the exact same problem.

I'd really like to fix this thing, and will even do it myself (if I
can manage it), but I don't know where to begin. I'm at my wit's end.
it's really frustrating.

Thanks for your help