Testing optos in switch edge test

Steps

• Open the coin door, press Begin Test and enter the test menu.
• Choose the switch edge test.
• Pass something through the opto beam to block it and watch for the switch to register.
• Remember optos read the reverse of a mechanical switch: an unblocked opto shows as a solid block on the dot matrix display.

Systems

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

Related tips

• Flipper cabinet opto switch boards
• Where WPC games use opto switches
• Keep opto switches clear
• Using the switch edge test
• How WPC opto switches work and which half fails
• Opto switches dead all at once
• Opto does not work: check 12 V at the transmitter connector
• Testing an opto receiver

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