System 11 backbox boards and supplies

The power supply makes +5 V for logic, +12 V and -12 V for audio, and +100 V and -100 V for the displays. The CPU/driver board holds the processor and drives all coils and matrix lamps, plus the flipper enable relay. The interconnect board links the harness to the CPU board and carries the flasher and lane change opto resistors.

Systems

• Williams System 11
• Williams System 11A
• Williams System 11B
• Williams System 11C

Related tips

• System 11 backbox boards at a glance
• What the System 11 power supply board feeds
• System 11 bridge rectifiers and their filter capacitors
• System 11 power supply versions D-8345 and D-12246
• Routine high-voltage changes on every System 11 power supply
• High-voltage supply rebuild parts, System 3 to 11C
• Game boots only sometimes, 5 V drops out: cracked diode D6 on the power supply
• +5 V fuse blows the instant the game is switched on

Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer