Bally -17 and early -35 games (before Xenon) to 115/120 V

Steps

• Remove the metal transformer cover in the backbox.
• The single red wire on the lower right lugs should go to pin 1 or pin 3.
• Fit one jumper between pins 1 and 3 and remove all other jumpers.

Line voltage is present in the power box, line cord and transformer wiring; unplug the game before working there.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35

Related tips

• The three Bally rectifier boards
• Checking the pre-Xenon supply with the game unplugged from it
• How the pre-Xenon power supply works
• Replacement pre-Xenon rectifier boards exist
• Logic 5 V reads over 5.25 V on Bally/Stern: the R49 boost resistor

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)