Lighting a whole lamp column by hand

Steps

• The eight lamp returns use N-channel 12N10L/IRL530 MosFETs Q45-Q52 on the driver board.
• With the game on, clip a test lead to ground and briefly touch it to one MosFET's metal tab.
• All lamps on that return line should light, showing whether the wiring and bulbs are good.

Systems

• Gottlieb System 3

Related tips

• Lamp and switch matrix size and drivers
• Coil or flasher on as soon as the game powers up
• A whole row of eight switches dead
• Spare MosFETs for the driver boards
• Logic chips worth stocking
• What the A3 driver board drives
• Bottom cabinet relays and their drivers
• Flippers dead in a game

Source: Repairing Gottlieb System 3 Electronic Pinball Games from 1989 to 1996, Clay Harrell (pinrepair.com)