Magnetic reed ball sensors on late WPC-95 games

From Safecracker and NBA Fastbreak on, Williams replaced eddy sensors with magnetic reed switches (Williams 20-10293), a black epoxy block about 2 inches by 1/2 inch. They need no extra board or even a diode, wire straight into the switch matrix like a microswitch, and rarely fail. Games using them include NBA Fastbreak, Safecracker, No Good Gofers, Cirqus Voltaire, Star Wars Episode I and Cactus Canyon.

Systems

• WPC-95

Games

• Cirqus Voltaire
• NBA Fastbreak
• No Good Gofers
• Safe Cracker
• Star Wars Episode I

Related tips

• Second-generation auto-adjust eddy sensors (1996-1998)
• Auto-adjust eddy board LED flashes constantly
• Opto styles used in WPC games
• Where WPC games use opto switches
• Some WPC-95 optos can fail even when they test good
• Real glass backglasses on a few WPC games
• How WPC opto switches work and which half fails
• WPC-95 five-leg Schmitt trigger U optos

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