How power reaches a System 1 game

The line cord feeds a line filter, then a line fuse and service outlet, then two transformers. There is no MOV surge suppressor. The large transformer gives 24 V for coils, 6.3 V AC for GI and about 6 V for CPU lamps; the small one gives about 60 V for the displays, 12 V for the logic supply and the 8 V and 4 V display references.

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

• The two System 1 transformers
• What is on the System 1 bottom panel
• Spare diodes, capacitors and other parts for System 1
• Power supply bring-up, step 1: inputs
• Testing a bottom panel bridge rectifier
• Replacement bridge rectifiers
• Coil, CPU lamp and GI supplies
• System 1 power supply outputs

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