Which rectifier to suspect for each blown fuse

F1: BR1 (or RP1/RP2 on a -49). F2: one of CR1-CR4, often shorted. F3: BR2. F4: BR3 or the varistor, or a short anywhere in the 43 V wiring (MPU, driver and sound boards included). F5: a short in the GI wiring. F6: a short in the line circuit; check the varistor and line filter.

Systems

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

Related tips

• Rectifier board and playfield fuse ratings
• F3, F4 or F5 blows on the rectifier board
• Hot, discoloured fuse clips
• GI fuse F5 blows at power-up and coils lack voltage: rectifier board wires in wrong pins
• Main solenoid fuse F4 blows (hard short)
• Rectifier test point ranges with fuse and rectifier
• What each rectifier on the board feeds
• Rectifier board test point voltages

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