Vintage Synth Repair

Ok, I somehow got bad reading on the channel non-correlation of the
missing vco.  Really baffled as to how.  I evaluated the schematics
thinking maybe there was something along the way that if a data line
was clamped somewhere it might cause that effect...but convinced
myself there wasn't some dual dynamic overlap thing going on, checked
again and found that it was the suspected thought that a solder blob
had gotten under something.  So now it play all vco's.

However it still quacks intermittently.  The quack is as someone
reminded me a warning buzz that can be turned down.  However it'd be
nice to figure out what's wrong there...and the BIG CLUE...is...there
is one button switch (yes which I'm having to manually do) which will
cause a quack every time.  PItch pedal!  Yup.  You hit it, you get a
quack.  Every time.  

And yes..I still need a membrane panel. I should look to see how hard
it would be to do a manufacturing run of those.  But if anyone at all
knows a source please let me know. Otherwise it'll be midi patch
changes for a while I guess...-Bob