Dedicated (coin door) switches

Eight coin door switches are wired straight to ground rather than through the matrix, so they still work if the matrix fails: D1 left coin (orange-brown), D2 center coin (orange-red), D3 right coin (orange-black), D4 fourth coin (orange-yellow), D5 service credits (orange-green), D6 volume down (orange-blue), D7 volume up (orange-violet), D8 begin test (orange-gray).

Systems

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

Related tips

• A dedicated (direct) switch does not work
• Game will not enter test mode
• Using the switch edge test
• Pressing the coin-door buttons does not enter test mode
• Check playfield switches with the switch edges test
• Switch 24, the always-closed switch
• Testing a switch diode out of circuit
• How the Williams switch matrix is scanned

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