the encoder on this moog "the source" was acting erratically. for the most part the encoder value just kept going gown, no matter what way you spun the wheel. sometimes it would start moving up, but then it would move to 99 and be stuck there.
after removing four screws on the bottom, and two on the rear panel, the synth opens up.
the encoder is an optical encoder with a clear plastic "disc" with dark lines on it, that pass through some sensor. the encoder was very dirty so the sensor was having trouble. i just carefully but thoroughly cleaned it up using iso-propyl alcohol. put it back together, and all worked as it should.
while i had it opened, i decided to replace some components in the power supply. one of the two 5v regulators is known for developing oxidization/corrosion on the legs which introduces noise on the 5v lines, and ultimately stops working entirely. someone had already been in there, and had set up a jumper from close to the body of the 5v regulator, over to a nearby diode.
so - i decided to replace both 5v regulators, and also the filter caps and big rectifier diodes.
i looked with an infrared camera and both diodes and caps were getting very warm, very quickly. i didn't get very good photos of that, but the diodes and the biggest filter cap lit up like a christmas tree on the infrared.
