Where the TIP122 drivers are on the CPU board
Q8-Q13, upper right: special coils. Q23-Q30, lower left: constant-power coils. Q39-Q46, lower left: multiplexed coils and flashers. Q72-Q79, lower right: lamp matrix row returns.
Systems
Related tips
- Solenoid driver transistor positions on the CPU and PPB boards
- Test each lamp row driver with a test lamp
- How the CPU-controlled lamp matrix is wired
- 50 V coils use PPB TIP36c transistors, pre-driven from the CPU board
- How a coil or flasher is switched: PIA to TTL to pre-driver to driver
- Multiplexed L/R (A/B) banks and wire colours
- Three-stage drive for 50 V coils
- The solenoid L/R select relay and transistor Q29
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part One, Clay Harrell (pinrepair.com)