Well, just completed my KISS restore... looks great and then start playing a few games and the right flipper goes out. All other lanes, targets, left flipper, etc work. I did notice the lowest bumper of the 4 closest to player does do a double bump when hit so I'm not sure if that is just an adjustment on the underside... checked the playfield fuse and that's intact.
so...
1) why would just the right flipper suddenly go out
2) why the double bump/chatter from one bumper only

BINGO! All the wires looked connected but one had just slightly loose solder... duh!
Thanks a lot!