Running a WPC CPU board on the bench

Steps

• Remove the CPU board from the game so it is isolated from the game's supplies.
• Use a switching arcade supply or a computer supply giving +5 V and +12 V. On computer supplies red is usually +5 V, yellow +12 V and black ground; confirm with a meter.
• Clip the supply to J210 (pin 1 at the top; same on all WPC boards): pins 1 and 3 ground, pin 2 key, pins 4 and 5 +5 V, pins 6 and 7 +12 V.
• On power-up a good board flashes all three LEDs briefly, the top LED goes out, the bottom stays lit and the middle starts pulsing quickly. Anything else is a fault.

Systems

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

Related tips

• What is on the WPC CPU board
• Bench-check the WPC CPU switch matrix circuit
• What fails on a WPC CPU board
• WPC CPU board versions and where they fit
• WPC-S and WPC-95 CPU boards need the matching security PIC
• Pre-WPC-S CPU EPROM size jumpers W1 and W2
• Country DIP switch settings on WPC-S and WPC-95 CPU boards
• Country jumpers W13 to W18 on pre-WPC-S CPU boards

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