Auxiliary lamp driver boards: SCR to connector pin

AS-2518-43: Q1-Q12 go to J2 pins 1, 2, 3, 5, 6, 7, 11, 12, 17, 20, 19, 18. AS-2518-52: Q1-Q14 go to J2 pins 7, 4, 8, 10, 9, 6, 5, 14, 11, 15, 18, 17, 13, 12, and Q15-Q28 go to J3 pins 8, 3, 9, 11, 10, 7, 4, 15, 12, 16, 18, 17, 14, 13 (page 35).

Systems

• Bally MPU AS-2518-35

Related tips

• Lamp driver, auxiliary lamp driver and display driver test points
• Auxiliary lamp boards drive special backbox lighting with MCR106 SCRs only
• Lamp driver board: which SCR drives which connector pin
• Controlled lamps flicker or stay out after fitting a replacement lamp driver with LEDs
• Lamp driver board layout: SCRs, decoders and connectors
• Substitute SCRs for the lamp driver board
• Lamp data and select lines: MPU J1 and lamp driver J4 pins
• AS-2518-14 vs AS-2518-23 lamp driver boards

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