Reading WPC switch numbers and the switch test display

A switch number is two digits: column first, then row, so switch 42 is column 4, row 2. In the switch tests the 8x8 box shows the matrix (a square is a closed switch, a dot open); the dot column to the left is the coin door switches and the one to the right the flipper switches. Unused columns are missing from the box, and the display shows the wire colors of the last switch closed.

Systems

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

Related tips

• How the switch matrix reads a switch
• WPC switch matrix basics
• A whole switch column dead or all closed
• A whole switch row dead or all closed
• "Ground Short Row" message
• A whole switch row or column is dead
• Switch 24, the always-closed switch
• How the Williams switch matrix is scanned

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