On my Star Trek TNG, the right lower flipper does not seem very strong in the up position - what happens is when you go to catch a ball, the ball hits it, slightly lowers the flipper, then it re-energizes, bouncing the ball back up the playfield!!
At first i thought it might be a dud coil, but a new coil has the same problem.
In switch edges the EOS works fine when you manually move the flipper, as well as when pressing the button. the lower left and upper right flippers are both fine.
I'm wondering if its the transistors on the fliptronics board - or is this more a mechanical problem?