Turn the display voltage down to 170 V

Steps

• With the game on, set the meter to DC volts.
• Put the black lead on TP10 (ground) and the red lead on TP2.
• Turn trim pot VR1 until TP2 reads about 170 V instead of the factory 190 V.

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

• Display high voltage above 190 V and VR1 cannot lower it
• High-voltage input fuse FU2 blows
• Replace high-voltage caps C6 and C7 before they take out Q2/Q3
• Score displays dead or dim: high-voltage section parts
• Power supply test points and their voltages
• Strange intermittent faults from power supply solder joints
• Where the boards sit in a 6803 backbox
• 6803 power supply fuse ratings

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