The display reports that F114 and F115 (F106 and F101 on WPC-95) should be checked, often with the fuses good.

"Check Fuses F114/F115" (F106/F101 on WPC-95) message

Cause: The game sees switch 24, which is wired always closed, as open. That happens when the switch supply is gone, but equally when U20 on the CPU board has failed. Blown fuses usually mean a shorted BR1 (D11-D14 on WPC-95), C6/C7 or regulator Q2; a blown F115 usually means U20 (perhaps with U14, or U23 on WPC-95).

Checks

• Pull and test both fuses.
• If F114 blows at once, suspect BR1 or C6/C7.
• If both are good, check the switch supply voltages (see the step-by-step entry), then switch 24's wiring, then U20.

Fix

• Replace BR1, C6/C7 or Q2 if the fuses blow.
• If the fuses are fine, replace CPU U20 (ULN2803), fitting a socket; if the message remains, replace U14 (74LS374), or U23 (74HC237) on WPC-95.

Systems

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

Related tips

• "Check Fuse F114/F115" (F106/F101 on WPC-95): step-by-step
• BR1 (D11-D14 on WPC-95) and the board around it scorched
• Row or column "ground short" errors
• WPC-89 CPU: one switch column still dead after a short: trace U14 to U20 to J206
• A whole switch column stops working: replace the ULN2803 column driver at U20
• Why CPU U20 fails and how to replace it
• Lamp matrix faults with all lamp transistors good
• Switch matrix chips on the CPU board

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