How System 11 A/C switched solenoids work
Solenoid drivers 1-8 each run two loads through the A/C select relay: bank A (mostly coils) and bank C (mostly flashers). With the relay at rest, power goes to bank A only; energized, power goes to bank C only. Q8 drives the relay; on the earlier 11 and 11A games it is Q7. The first two games, High Speed and Grand Lizard, have no bank switching.
Systems
Games
Related tips
- Special solenoids dead after fitting an early System 11 CPU in a later game
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- How the System 11 A/C bank select works
- Where the coil diodes are on System 11
- A-bank coil not working
- Special solenoid signal path, chip by chip
- Later System 11 moved relay and diode boards to the backbox
- The six special solenoids (pops, slings, kickbacks)
Source: Repairing Williams System 11 Pinball 1986 to 1990, Deel 1, Clay Harrell (pinrepair.com)