Lamp and switch matrix transistor positions on the CPU board
2N5060 parts at Q81-Q88 pre-drive the TIP122 lamp-row returns. TIP42 transistors at Q64-Q71 switch the 18 V onto each lamp column. 2N6427 parts at Q56-Q63 pre-drive the TIP42s. 2N3904 transistors at Q48-Q55 drive the switch matrix columns.
Systems
Related tips
- Lamp matrix still wrong after replacing transistors: upstream parts
- How the CPU-controlled lamp matrix is wired
- Monday Night Football: switch column transistor Q54 keeps failing
- Switch row or column error: CPU board or playfield?
- Switch column (drive) circuit on the CPU board
- Lamp row still dead after a new TIP122
- Lamp column still dead after a new TIP42
- Test each lamp column driver with a test lamp
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)