Testing a bottom panel bridge rectifier

Steps

• Game off. Set the meter to diode test.
• Red lead on the ground (negative) lug, which has the green wire; black lead on each AC lug beside it in turn. Each should read 0.4 to 0.6.
• Black lead on the positive lug (diagonal from ground, or the one turned 90 degrees on newer bridges); red lead on each AC lug in turn. Each should read 0.4 to 0.6.
• Any other reading means the bridge is bad.

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

• What is on the System 1 bottom panel
• Spare diodes, capacitors and other parts for System 1
• How power reaches a System 1 game
• Bottom panel fuses on System 1
• The two System 1 transformers
• Coil, CPU lamp and GI supplies
• Power supply bring-up, step 1: inputs
• None of the CPU controlled lamps light

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