Resets; arcing marks around the main fuse holder in the power box.

Resets from a loose or burnt line fuse holder

Cause: The line fuse holder is not robust and can loosen; the fuse itself can also develop resistance.

Checks

• Unplug the game and inspect the fuse holder and fuse for burn marks or looseness.

Fix

• Replace the line fuse holder and fuse.

Unplug the game: the power box carries line voltage.

Systems

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

Related tips

• WPC: fuse holder snaps off the power driver board: replace the clips properly
• F111, F112 or the line fuse keeps blowing
• WPC-95 line fuse
• Test every fuse properly before first power-on
• WPC power driver board fuses and what they feed
• Line fuse that blows only with the coin door closed

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