WPC-95 filter capacitors are smaller (10,000 mfd)

WPC-95 boards use 10,000 mfd at C9 instead of the 15,000 mfd C5 on older boards, so they may become more sensitive to aging caps. Bigger capacitors filter better as they age but raise the turn-on inrush current through the bridge or diodes, which can be ten times the running current and can open a bridge.

Systems

• WPC-95

Related tips

• Filter capacitors and GI triacs that fit WPC boards
• Checking a filter capacitor for ripple
• Choosing a replacement driver board filter capacitor
• WPC-95 rectifier diodes, filter caps and fuses by supply
• +20 V filter capacitor C11 (C10 on WPC-95) blows apart
• WPC-95 LED101 off (+5 V, game will not boot)
• Testing a WPC-95 rectifier diode
• WPC-95 driver board LEDs and test points

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