try checking the diodes on the keybed
i had the same problem on 2 esq1 keybeds
there were a few shorted diodes and when you
pressed certain keys they would permently drone certain voices
found the problematic diodes replaced and all was
fine
try just triggering from an external device or
sequencer to see if all notes respond properly
thats what i did for both once i found all the note
played correctly then i knew it was not the uart or keyboard scanner
chips
----- Original Message -----From: Adrian CorstonSent: Saturday, May 26, 2012 3:44 PMSubject: Re: [vintagesynthrepair] PPG Wave 2.3 power supply restoration (working, now for the other repairs :-)Thanks Kris and others,
I replaced the bridge rectifier and cleaned all the gunky flux off the
+5V power supply board soldering; now I have good power but some very
strange voice behaviour (display works correctly; values on the analog
page respond to knob turns correctly; voice 1 drones occasionally;
keyboard does not play notes properly although aftertouch does have some
effect; some waves produce distorted sounds but most don't; bender and
mod wheel affect the droning oscillator as expected; etc etc.) Time to
break out the CRO and see what I can find wrong next.
Thanks for your help!
Cheers,
A.