Routine high-voltage changes on every System 11 power supply
Fit new flame-proof 39k resistors at R1 and R4 as a matter of course, and when rebuilding the section also change ZR2/ZR4 to 1N4763A zeners.
The display supply runs at about 100 V DC (plus and minus) with large filter capacitors; work with the game off and unplugged, and measure live only with insulated probes.
Systems
Related tips
- High-voltage supply rebuild parts, System 3 to 11C
- What the System 11 power supply board feeds
- System 11 power supply versions D-8345 and D-12246
- Display voltages at 3J2, power supply D-11883/D-12246 (Taxi to Dr. Dude)
- Fitting the high-voltage kit
- Rebuilding the +100 V section of the power supply
- Rebuilding the -100 V section of the power supply
- GI connectors left the power supply after Cyclone
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell