My prodigy has developed an issue where the envelopes no longer function. The last note played sustains forever, and the adsr controls for the filter and vca have no effect. It does respond to the keyboard in terms of the note being played, but it is like a gate on that never gates off, no variance at all in the amplitude or timbre during the duration of the note. I verified that I am getting a trigger from the keyboard, and an S trigger is being generated, but I'm not getting the -12 volts on pin 5 of dual timer U23 called for in the manual, I'm getting a positive 12 volts. Any suggestions on what I should check next would be greatly appreciated, I'm not sure if that implies an issue with U23 or with the switch U18.
Markh