Replace the +5 V filter capacitor on any game ten years or older

A worn C5 (15,000 mfd 25 V; C9 on WPC-95) leaves the 5 V rough and causes random resets. Replace it when replacing BR2, and on any game ten or more years old, and replace C4 (C1 on WPC-95, 100 mfd 25 V) with 470 or 1000 mfd.

Systems

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

Related tips

• Reboots at start-up and when flipping: flaky power connector to the CPU
• Game keeps resetting during play: poor J101/J102 power connections
• Resets when a drop target or coil fires: burnt power and GI connectors
• Game reboots the instant the second visor lock is made in later multiballs
• Resets when the knocker fires, hum and DMD glitches: cracked power board joints
• Resets during the Powerball battle: reseat J101 and J115 on the power driver
• What a WPC game reset is
• Resets: +5 V at the driver board test point is low

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