I'm working on a GNR that has flippers that move very slowly. The upper left flipper doesn't work at all. When I activate the left flipper, hold it, then activate the right flipper, the right flipper moves even slower. Both lower flippers have been rebuilt with new everything. I also tried a working flipper board from another game and got the same results.

I tired a known good PPB board and my upper left flipper now works. Another thing to note is the only the bottom LED on the flipper board lights when the left flipper button is pressed. No LED lights when the right flipper button is pressed.

After the replacement PPB the upper flipper worked. I had the wires off the EOS switches. I jumped the wires and everything worked perfectly. I soldered the wires to the EOS switches and everything was still good. I played a game with the glass off and backbox open. Still good. I then turned the game off, put everything back together, turned on the game and now I'm back to the upper flipper not working and both lower flippers being really slow. Checked all fuses with a meter and non are blown.