System 3 fuse chart

Power supply: F1 display 90 VAC 1/4 A slow; F2 solenoids 28 VDC 2.5 A slow; F3 lamp matrix 18 VDC 8 A fast; F4 GI 6.3 V 20 A fast on Hot Tip and Lucky Seven only (unused from World Cup); F5 +5 V logic 4 A fast. Sound board F1 9.3 VAC 4 A slow (some schematics say 2 A). Fuse card below the power supply: 28 V flippers 20 A fast (not on Hot Tip/Lucky Seven). Under the playfield: flippers 10 A fast.

Systems

• Williams System 3

Games

• Lucky Seven

Related tips

• Fuse values to keep on hand for System 3-7
• Games built on System 3
• Testing a fuse
• Where the flipper fuse is by generation
• Sound EPROM files used by System 3-6 games
• Add fuses to the inputs of the backbox bridges
• Pull the coil and lamp fuses for the first power-up
• Pull fuses F2 and F3 until the CPU board runs properly

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