While troubleshooting, the 12 V supply at J139 measures about 15.8 V instead of around 12 V.

12 V supply reads nearly 16 V: transformer only half converted to 110 V

Cause: The game had been converted from another mains voltage to 110 V, but only part of the transformer wiring had been moved, so some secondaries were running high.

Checks

• Measure the main DC supplies at the power driver board connectors and compare them with the manual.
• Compare the transformer primary jumper or plug wiring with the manual's chart for the local line voltage.

Fix

• Move the remaining transformer wires to the correct positions for 110 V (re-terminate with the proper pins), then recheck the voltages; here the 12 V dropped to about 12.5 V.

The transformer primary is at line voltage: unplug the game before touching the transformer wiring.

Systems

• WPC-95

Games

• Cirqus Voltaire

Related tips

• WPC transformer part numbers
• WPC transformers look alike but are not interchangeable
• Trace the 12 V switch supply with the playfield disconnected
• Driver board supply test points and normal readings
• WPC-95 uses discrete P600D diodes instead of bridges
• WPC-95 rectifier diodes, filter caps and fuses by supply
• WPC-95: a dark +20 V LED at TP104 means the flasher supply is not leaving the board
• WPC-95 LED102, LED103, LED104 or LED105 off

Source: Pinball Repair help group!! (Facebook group)