Power supply bring-up, step 1: inputs

Steps

• Game off: pull and continuity-test every bottom panel fuse, and confirm ratings and types (SB or NB).
• Unplug power supply J2 (top) and J3 (right); leave J1 (bottom) plugged in, the right way up.
• Power on and read the AC inputs at A2-J1: pins 1-2 about 11.5 V AC (white/blue, white/orange), pin 3 ground, pins 4-5 about 14 V AC (white/brown, white/purple), pins 6-7 about 69 V AC.
• Then read the J2 and J3 outputs before plugging anything else in.

The bottom panel carries 120 volt line power; unplug the game before touching the transformers, line filter or fuse block.

Systems

• Gottlieb System 1

Related tips

• Power supply bring-up, step 2: CPU load
• Power supply bring-up, step 3: displays
• System 1 power supply outputs
• Replacing power supply filter capacitor C1
• Getting to the power supply solder side
• Quick checks on the similar System 1 power supply
• Display high-voltage section of the power supply
• Logic and display reference section of the power supply

Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)