Adding backup jumpers to a WPC-95 driver board

Steps

• The jumpers protect the heavy filter capacitor joints, which crack from vibration; the diodes themselves do not need them.
• At minimum do the +5 V set: non-banded side of D7/D8 to C9 "-", banded side of D9/D10 to C9 "+".
• 12 V unregulated: non-banded side of D5/D3 to C8 "-", banded side of D4/D6 to C8 "+".
• 18 V lamp and 12 V regulated: non-banded side of D11/D12 to C11/C12 "-", banded side of D13/D14 to C11/C12 "+".
• 50 V coils: non-banded side of D19/D22 to C22 "-", banded side of D20/D21 to C22 "+".
• 20 V flashers: non-banded side of D16/D18 to C10 "-", banded side of D15/D17 to C10 "+".

Systems

• WPC-95

Related tips

• WPC-95 driver board LEDs and test points
• Supplies made on the WPC power driver board
• WPC-95 LED101 off (+5 V, game will not boot)
• Testing a WPC-95 rectifier diode
• WPC-95: all the 20 V coils dead, fuse good
• Driver board filter capacitors wear out
• Filter capacitors and GI triacs that fit WPC boards
• WPC-95 LED100 off (+12 V regulated)

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