On my Genie, the right upper mini flipper flips rapidly most times that you hit the flipper. Other times it works OK. Other times it doesn't even flip when you hit the button. The lower flippers all work just fine without any issues. Does anyone know what might cause this?

Also, is it normal for both upper mini flippers to have a tiny delay - they don't quite flip at the exact same time as the lower flippers. Thanks guys.

I'll check out that mod, but more importantly....still getting that rapid upper right mini flipper. Seems to happen after a couple minutes. So I rebuilt every flipper in the game - all new parts. EOS switches are all perfectly gapped. Still happens.

The flipper buttons themselves only have one switch each and the lower flippers never flip rapidly. I cleaned the switches so make good contact anyway, but same issue. Anything else to check?

I did, and I checked that a bunch of times...but what I didn't realize is the switch for the uppers are actually on the lowers (you mentioned this atop the thread but I misread it as the switch was at the buttons). This is my first older solid state so I'm still kinda figuring out what everything does. Realizing the upper flipper switch is basically an EOS switch on the lowers, I just changed the gap to be very tight rather than 1/8".

This fixed BOTH issues....now the upper flippers flip exactly with the lowers (I'm sure there's a tiny delay but it's not noticeable) and the upper right no longer jitters.

Hey RacingPin - jusy FYI, all that work you did isn't really necessary....just make the switch gap shorter on the lowers and they flip exactly like modern games with uppers.