Lamp driver board layout: SCRs, decoders and connectors
There is no lamp matrix. The board has 24 MCR106-1 SCRs (each can light two bulbs) and 36 smaller 2N5060 SCRs, for 60 controlled lamps, each SCR gate driven by one output of four CD4514 decoders. J1 and J3 (28 pins each) go to the playfield and J2 goes to backbox lamps such as Game Over, Tilt, Match, High Score and Ball in Play.
Systems
Related tips
- Lamp driver SCRs on the CPU board
- Lamp driver board: which SCR drives which connector pin
- Substitute SCRs for the lamp driver board
- Test a 2N5060 lamp matrix SCR with a meter
- Lamp driver SCR blew apart with a crack
- AS-2518-14 vs AS-2518-23 lamp driver boards
- Test lamp SCRs with the power off
- Lamp and switch matrix transistor positions on the CPU board
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)