The solenoid L/R select relay and transistor Q29
Transistors Q39-Q46 each serve two devices, chosen by the PPB board's solenoid L/R select relay (banks may be marked L/R or A/B). CPU transistor Q29 drives that relay. Usually the L (A) bank carries coils and the R (B) bank flash lamps.
Systems
Related tips
- Multiplexed L/R (A/B) banks and wire colours
- Solenoid driver transistor positions on the CPU and PPB boards
- 50 V coils use PPB TIP36c transistors, pre-driven from the CPU board
- Three-stage drive for 50 V coils
- Where the TIP122 drivers are on the CPU board
- How a coil or flasher is switched: PIA to TTL to pre-driver to driver
- How the CPU-controlled lamp matrix is wired
- Test each lamp row driver with a test lamp
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)