Sys3 flippers are relatively simple as they never went to a full digital flipper system, rather using a sensor board to determine when the flipper buttons are pressed.
It looks like your flipper is wired correctly, though I can't tell how the cap is wired (should be across the switch.) Assuming this is a new coil and diode from PBR. Best to check the coil resistance. Might be a bad diode or cap. Also check wiring to make sure there's no short elsewhere in the chain.
viperrwk