After moving the game, neither flipper works in a game and neither cabinet flipper switch registers in switch test, yet the flipper coils fire in the coil test and the upper (diverter) buttons work.

Both flippers dead in game but fire in coil test: loose old wire splice at J116

Cause: The coils and drivers are fine; the flipper switch inputs are missing. Here a wire into connector J116 that had been spliced and taped by an earlier owner had come apart. The cabinet flipper opto boards share power and ground that run from one board to the other, so one break can kill both flippers.

Checks

• Confirm the coils fire in coil test and the flipper buttons do nothing in switch test.
• Check both cabinet flipper opto boards: connectors fully seated, LEDs and power present.
• Follow the opto boards' power, ground and signal wires back toward the backbox, looking for old splices and tape, especially at J116.

Fix

• Repair the broken wire properly (solder and heat-shrink, or repin the connector) and retest the flippers in switch test and in a game.

Systems

• WPC-Security (WPC-S)

Games

• The Shadow

Related tips

• Fliptronics and WPC-95: weak flipper
• One GI string dead though the board and fuse test fine: burnt connector in the cabinet
• Flippers and magnet weak after rebuilds: replace the Fliptronics board
• Games that came with Type 2 flipper opto boards
• Trough eject and left sling dead together: reseat the CPU to driver ribbon
• No 50 V coils work
• One coil will not fire
• One coil does nothing in the solenoid test

Source: Pinball Repair help group!! (Facebook group)