The playfield GI stays off when play switches from video to pinball.
Baby Pac-Man playfield GI never comes on for pinball mode
Cause: The GI is switched by a triac on a small driver board fed from a lamp driver SCR; no controlled-lamp power (fuse) or a failed SCR leaves it off.
Checks
- Check whether the controlled lamps work at all, then test the SCR that drives the triac board.
Fix
- Restore the lamp power or replace the SCR.
Systems
Games
Related tips
- A playfield target lamp never turns off
- Two inserts faintly lit all the time: failed lamp driver SCR
- One controlled lamp dead even after a new SCR: lamp driver board fault
- On Baby Pac-Man and Granny, a GI fuse kills the feature lamps
- Lamp driver, auxiliary lamp driver and display driver test points
- How Bally controlled lamps are powered and switched
- Lamp driver board layout: SCRs, decoders and connectors
- One controlled lamp does not light
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)