Bally board assembly numbers
MPU boards are AS-2518-17 and AS-2518-35; the power transformer module is AS-2877-6; the solenoid driver/voltage regulator is AS-2518-22; the lamp driver is AS-2518-23 and the auxiliary lamp driver AS-2518-52. Sound boards include AS-2518-50, Sounds Plus AS-2518-56, Vocalizer AS-2518-57, Squawk & Talk AS-2518-61B and Say It Again AS-2518-81. Display drivers are AS-2518-21 (6 digit) and AS-2518-58 (7 digit).
Systems
Related tips
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part One, Clay Harrell (pinrepair.com)