Jokerz flipper problem

Agreed, and replace with correct orientation as well or you'll do it again.
Diode orientation is about halfway down the page in the link

http://homepinballrepair.com/index.php/pinball-flipper-rebuilding-how-to-fix-and-replace/

Also, because you are experiencing potentially 2 separate issues (l and r flipper behavior is different), you may want to fix the diode flipper issue first, check for function, then work on the dead one. Better to isolate than to guess