[HELP] Not sure where to post this but this seems like a good start - Linear encoder repair

[EdK]

Those black ones with the stripe are either diodes or capacitors. My guess is capacitors since they would be awfully large wattage diodes for circuitry that runs on such low DC voltage. Ron is probably correct about the "fish eye" parts being photo transistors or diodes.

I would give the printed circuit boards a good scrubbing with some alcohol from the paint department and try seeing if that fixes your problem. You could also use rubbing alcohol but try to get some that doesn't have oil in it.

Ed