How the Tilt and Game Over lamps are switched

Both backbox lamps run on 6.3 V AC GI power through relay contacts: the Tilt lamp through a normally open T relay contact, and the Game Over lamp through a normally closed Q relay contact, so it goes out when a game starts.

Systems

• Gottlieb System 1

Related tips

• None of the CPU controlled lamps light
• What the Game Over (Q) and Tilt (T) relays do
• Backbox or playfield GI always off
• What happens when the T relay pulls in
• Hold the Q relay in to test flippers and bumpers
• Pop bumper or slingshot locked on or dead
• What the Q relay contacts switch
• How CPU-controlled lamps are driven

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