50 V coils use PPB TIP36c transistors, pre-driven from the CPU board
On PPB games each 50 V coil is grounded through a TIP36c on the PPB, which is switched by a TIP122 on the CPU board. MRB games have no TIP36c; they switch 50 V coils with relays mounted under the playfield.
Systems
Related tips
- Solenoid driver transistor positions on the CPU and PPB boards
- How a coil or flasher is switched: PIA to TTL to pre-driver to driver
- Three-stage drive for 50 V coils
- Where the TIP122 drivers are on the CPU board
- The solenoid L/R select relay and transistor Q29
- How the CPU-controlled lamp matrix is wired
- Multiplexed L/R (A/B) banks and wire colours
- Solid state flipper very weak: power side has failed
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part One, Clay Harrell (pinrepair.com)