Hitting a slingshot tilts the game or confuses the switches; in the worst case the MPU PIA chips are damaged.
Slingshot switch causes a tilt, or PIA chips fail
Cause: Bare slingshot switch wires break and touch the grounded plunger spring, or touch the coil lugs and put 43 V into the matrix.
Checks
- Inspect the slingshot switch wiring under the playfield for breaks and contact with the spring or coil lugs.
Fix
- Repair and dress the wires away from the spring and coil; replace damaged PIAs.
Systems
Related tips
- Rollover switch only registers with two diodes fitted: failing PIA at U10
- MPU switch connector pins J2 and J3
- Stand-up target always closed in test and ghosting another: failed switch capacitor
- Prove the MPU switch inputs with the harness unplugged
- Coin door switch shorted to ground causes lamp and other odd faults
- Tilt doesn't work and closing it fires a pop bumper: dirty slam tilt switch
- Pop bumper or slingshot fires by itself; random tilts
- Hitting switches in one matrix row tilts the game: bad capacitor on the tilt bob
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)