Turn the game off when not playing
Displays wear in proportion to hours on, connectors burn on games left powered, GI heat can warp plastics and lift backglass paint, and running fans and transformers pull dust into the game. A game of this era draws about 4 A in attract mode, roughly a 240 W load.
Systems
Source: Repairing Williams System 11 Pinball 1986 to 1990, Deel 1, Clay Harrell (pinrepair.com)