Power supply test point ranges

TP1 +5 VDC (4.9 to 5.2); TP2 170 to 190 VDC display supply; TP3 about 230 VDC unregulated display input; TP4 +43 VDC (40 to 60) coils; TP5 +14 VDC unregulated (11 to 16); TP6 and TP7 11 VAC lamp phases A and B; TP8 and TP9 6.3 VAC GI (5.8 to 6.8); TP10 ground.

The display supply runs at 170-230 volts DC; touch nothing on the high-voltage section with the game on, and let it discharge before working on it.

Systems

• Bally 6803

Related tips

• Power supply test points and their voltages
• No +5 V at TP1 or no 14 V at TP5
• Check every power supply fuse before first power-up
• No 43 V for the coils
• Replacing the 78H05 +5 V regulator
• Bad +5 V bridge diodes D1-D4
• +5 V still bad with good C1 and diodes
• 6803 power supply fuse ratings

Source: Repairing Bally 6803 Pinball Games from 1985 to 1989, Clay Harrell (pinrepair.com)