Pull the coil and lamp fuses for the first power-up

Steps

• Remove F2 (solenoids) and F3 (lamp matrix) from the power supply board before the first power-up.
• Power up and get the CPU and driver boards working first.
• Refit the fuses once the boards boot normally.

Systems

• Williams System 3
• Williams System 4
• Williams System 6 / 6A
• Williams System 7

Related tips

• Pull F2 and F3 when first powering an unknown game
• Pull fuses F2 and F3 until the CPU board runs properly
• Bring a repaired board set back into the game
• First power-up check on a dead game
• Flippers dead: fuse and coil voltage
• Solenoid fuse blows as soon as the game is turned on
• Power circuits in a System 3-7 game
• Where flipper power comes from

Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part One, Clay Harrell (pinrepair.com)