I broke the shaft of the "middle" pot by trying to remove the knob: I removed the set-screw, pulled... pulled harder, and the shaft came out with the knob still on it. So, now that I've replaced it, I disassembled the broken pot. Photo here:
http://picasaweb.google.com/lh/photo/fxk1rFMUXQJ68YQLYQmKNg?feat=directlink
The shaft, which looks large and strong, tapers to the diameter of a wire. On the end is tiny disc. The disc slips through a keyhole fitting in a small white piece of plastic, which holds the metal contact of the switch. Moving the metal to the back of the switch allows it to contact the solder lugs on the rear, completing the circuit.
So... important safety tip: don't pull hard on the knob if trying to remove one. For the others I shot some WD-40 into the set-screw holes and waited ten minutes before trying to remove them. That worked well.
http://picasaweb.google.com/lh/photo/fxk1rFMUXQJ68YQLYQmKNg?feat=directlink
The shaft, which looks large and strong, tapers to the diameter of a wire. On the end is tiny disc. The disc slips through a keyhole fitting in a small white piece of plastic, which holds the metal contact of the switch. Moving the metal to the back of the switch allows it to contact the solder lugs on the rear, completing the circuit.
So... important safety tip: don't pull hard on the knob if trying to remove one. For the others I shot some WD-40 into the set-screw holes and waited ten minutes before trying to remove them. That worked well.
