The connectors that burn most often

The 20 pin .156" J3 on the rectifier board of pre-Xenon Bally and all Stern games, especially pin 8 (orange), and pin 12 (orange) of the 25 pin .100" J3 on the solenoid driver board.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200

Related tips

• AS2518-18/-49 connector functions
• Which boards use .156" and .100" connectors
• Key new connector housings
• Connector housings and pins to keep on hand
• Check the mating connectors after a corrosion repair
• Pre-Xenon rectifier board outputs by connector
• Burnt rectifier J3 pins 8 and 17

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part One, Clay Harrell (pinrepair.com)