Flipper enable relay K1 on the CPU board
K1 on the CPU board (4-pole, 40 ohm, 6 V) switches the flipper coils' ground, so the flippers work only in play and in diagnostics. You should hear it click on when entering diagnostics.
Systems
Related tips
- No flippers at all: flipper relay K1 not pulling in
- Listen for flipper relay K1 when entering diagnostics
- How relay-enabled flippers work
- Checking ground and +5 V on the CPU board
- Test points for relay-style flippers
- Which System 11 CPU boards fit which games
- System 11 CPU board connectors
- Running the CPU board on the bench
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell