What each rectifier on the board feeds

BR1 (-18 only): 7.8 V AC to about +5.5 V DC through F1 for the feature lamps (RP1/RP2 on the -49 give 6.5 V from 9.2 V AC). BR2: 12 V AC to 11-16 V DC through F3, for the regulated +5 V logic. BR3: 49 V AC to +43 V DC through F4, for all coils including the knocker, and the sound board on many games. CR1-CR4: 173 V AC to +230 V DC through F2 for the displays.

Systems

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

Related tips

• Rectifier board test point voltages
• The three Bally rectifier boards
• Upgrading the AS2518-18 / -49 rectifier board
• Bench testing a rebuilt rectifier board
• Rectifier test point ranges with fuse and rectifier
• Where the 43 V solenoid supply leaves the rectifier board
• No +12 V at rectifier board TP3
• Random reboots during play: reflow the rectifier board

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