There may be some merit to your idea John. I got out my trusty digital strobe tuner and everthing seemed close enough to concert to be only a short tweak of the master tune from dead on. However on further inspection I discovered that every voice's octaves are out significantly. Both on the keyboard and when engaging the UP/Down octave buttons. This was on all voices (including one I'd recently calibrated) so it does point to some problem with the master control of volts per octave. May it is some corrosion in a pot which would make sense considering it sat unused for a couple months. I will explore this further tomorrow. This would certainly baffle autotune correct?
@Bob, I'm going to explore this avenue and hopefully I won't have to replace any ICs... If I do though I have unfortunately gotten pretty good at removing and socketing them (thanks to this board). Thanks for the pointers though. I wish I'd gotten that with the first one I tried to remove... I destroyed the (non-valuable) IC... but that was not my intention lol. Now I have a nice desolder station with a few nice suction pumps too.
Though just replacing slews of these seems like a good weekend project as the components begin to have the misfortune of being manufactured a long time ago. Especially after John's story.
Sincerely,
Rich Clarke