The right flipper on Corvette just suddenly stopped working. Since I had recently installed a new flipper button on that side, I went in to the switch test.
I found the left flipper's two switch optos were tight, but the right had a flakey second one! Reseating the cable seemed to help a bit in the switch test, but still the flipper didn't work.
I ended up removing the fliptronic board:
I cleaned the optos with windex and cleaned the board as a whole. This improved the performance in the switch edge test!
But, still flipper didn't work. Under the playfield, the solution was obvious: wire had disconnected from the flipper coil's lug. Ooops.
Lesson learned: Start at the beginning and work backwards, even if you have a hunch where you think the problem might be from.
At the very least, cleaner opto board!
I don't even think the second opto mattered at all though, since there is only a single flipper on the right side.