WPC-95 five-leg Schmitt trigger U optos

WPC-95 games switched to a five-leg U slot opto with a Schmitt trigger (a 3-leg receiver plus a 2-leg emitter). These either work or don't; they do not flicker on and off as they get dirty or old, which makes flipper opto faults much easier to diagnose than on the older four-leg optos.

Systems

• WPC-95

Related tips

• Replacement five-leg U slot opto (WPC-95)
• Opto styles used in WPC games
• Where WPC games use opto switches
• Some WPC-95 optos can fail even when they test good
• How WPC opto switches work and which half fails
• Testing an opto receiver
• Opto parts to keep on hand
• Cleaning dusty optos

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