System 11 coil outputs
The CPU/driver board has 16 coil outputs and 6 special solenoid outputs, all TIP122 Darlingtons switching to ground. The coil diodes are not on this board, and coil power comes from the auxiliary power driver board, or on early games from a bridge rectifier on the backbox wall.
Systems
Related tips
- Sling or bumper locks on at power-up (System 11)
- System 11 CPU/driver board transistor locations
- Three-stage drive for 50 V coils
- 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
- 50 V coil dead on an early System 11 game
- Kicker coil locks on again after a new TIP122: dead 7408 gate on the driver board
- F5 blows on a flip, then slings dead: shorted drivers and a loose coil power wire
Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer