The three Bally rectifier boards

AS2518-18 is the common one (and identical to Stern's) and needs upgrades. AS2518-49, used only on Kiss, Future Spa and Space Invaders, also needs upgrades. AS2518-54, used from Xenon on, is sound and usually needs only new header pins.

Systems

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

Games

• Future Spa
• Space Invaders

Related tips

• Fuses blow with a brand new rectifier board: cold joint on BR1
• What each rectifier on the board feeds
• Rectifier board test point voltages
• 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

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