The test report flags an upper flipper switch on a game without upper flippers.

Upper flipper switch reported bad on a game with no upper flipper

Cause: From The Addams Family on, every flipper opto board has two optos, one for a lower and one for an upper flipper, and some software reports the unused one. Usually its interrupter never leaves the opto's U.

Checks

• Watch whether the interrupter fully clears the second opto.

Fix

• Bend the activator so it clears the U, or replace the opto.

Systems

• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• Fliptronics: flipper button does not register in switch test
• Upper flipper sometimes weak, then buttons dead after cleaning: replace the flipper optos
• One flipper dead and its button fails switch test: dirty flipper button opto board
• Fliptronics and WPC-95: weak flipper
• Flipper stuck up but drops when the power goes off
• Flipper stays up briefly after the button is released
• Fliptronics: flipper will not hold up (flutters)
• All flippers kick once at game start and then go dead

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Two, Clay Harrell (pinrepair.com)