Lamp driver, display and sound board test points
Lamp driver and auxiliary lamp driver: TP1 +4.9 to 5.2 V, TP2 ground. Display drivers: TP1 +4.9 to 5.2 V, TP2 +190 V, TP3 ground. Sound module -32: TP1 +5 V, TP2 ground, TP3 +11.9 V, TP4 and TP5 +43 V. Sound module -50: TP1 +5 V, TP2 ground, TP4 +43 V. Squawk & Talk -61: TP1 ground, TP2 +5 V, TP3 +11.5 V, TP4 -5 V.
The score display supply runs at 170-230 V DC; keep hands off the rectifier and driver boards with power on.
Systems
Related tips
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part One, Clay Harrell (pinrepair.com)