Microswitches wear out and are easily damaged by soldering heat

A microswitch is rated for about 100,000 closures, and a busy switch such as the shooter lane can pass that on a well-played game, so most microswitches in a used machine are close to worn out and may go sticky or intermittent. More often the metal actuator has been bent down by the ball; rebend it with the game off. Use little heat when soldering, since the plastic body melts easily.

Systems

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

Related tips

• Wiring a microswitch into the matrix
• Testing a diode on a matrix microswitch
• Testing a microswitch diode without unsoldering it
• Microswitch with a broken terminal tab: replace the switch, don't move the wire

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