Find a bad trough switch with Easy Trough Clear

Steps

• In the diagnostics choose "Easy Trough Clear".
• Each flipper press kicks one ball to the shooter lane, and the display shows how many balls the game believes remain.
• Clear the balls one at a time and watch for a count that is wrong or a ball that does not roll down.
• Then open the switch test and close each roller switch: only that switch should show. Two at once points to a matrix short or wiring error.

Systems

• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Games

• Batman Forever
• Baywatch
• Guns N' Roses
• Jurassic Park
• Last Action Hero
• Mary Shelley's Frankenstein
• Maverick
• Tales from the Crypt
• The Who's Tommy Pinball Wizard
• WWF Royal Rumble

Related tips

• Ball trough optos from Baywatch on
• Which Sega games use optical switches
• Ball ends early for no reason: missing switch diodes on the ramp switches
• Flipper EOS switch role from Jurassic Park on
• Three-ball troughs on early Data East games
• Jurassic Park and later: the solid state EOS switch
• Baywatch and Batman Forever: reaching the switch and lamp tests

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)