Hold in the Game Over "Q" relay to test coils in attract mode
The Q relay under the playfield pulls in when a game starts and switches on power to the playfield coils. With the game in attract mode you can carefully hold it in by hand to power the flippers, pops and slings without starting a game, which helps when adjusting flippers or testing the pop bumper driver board. Don't knock its armature plate off its pivot.
Systems
Related tips
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)