A feature lamp stays lit.
A playfield target lamp never turns off
Cause: A shorted lamp driver SCR, or a leaky capacitor on the switch that sets that lamp.
Checks
- Ground the SCR gate (lamp always on procedure); clip the switch capacitor to see if it clears.
Fix
- Replace the SCR or the switch capacitor.
Systems
Related tips
- One controlled lamp does not light
- Baby Pac-Man playfield GI never comes on for pinball mode
- AS-2518-14 vs AS-2518-23 lamp driver boards
- Test lamp SCRs with the power off
- Substitute SCRs for the lamp driver board
- Lamp driver, auxiliary lamp driver and display driver test points
- How Bally controlled lamps are powered and switched
- Two inserts faintly lit all the time: failed lamp driver SCR
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)