5V reset board fix.
Plug in Reset Fix Board with led voltage display for the Bally / Williams WPC pinball System part # A-12697-1, A-12697-3, A-12697-4 power / driver boards.

The Reset Fix Board prevents the shut down and SHOWS YOU THE EXACT VOLTAGE ON ITS LED DISPLAY AT J120. Easy plug and play.

How it works: When a game suddenly shuts off, goes dark and reboots itself after a few second delay, an MPU board reset has occurred. Unwanted resets occur on WPC pinball machine MPU boards because the Power Driver Board's (PDB) 5 volt power supply is marginally designed for the many circuits it drives.

The Reset Fix Board creates a unique 5 volt power source for the WPC System MPU board.

WPC series MPU boards have a watchdog circuit that shuts down the board if the 5 volt power supply drops below a cutoff voltage (~ 4.7 volts). This happens more frequently as game circuitry ages, and the machine unexpectedly turns off and ends any active games. Ironically, the watchdog circuit shut down often reduces the 5 volt load, the voltage quickly recovers, and the machine restarts normally.

Unfortunately, the problem persists and re-energizing the MPU board quickly loads down the 5 volt power supply and the watchdog again resets the MPU.

The Reset Fix Board eliminates watchdog circuit resets by removing the MPU load from the PDB 5 volt circuit and re-routing it to the more powerful 12 volt circuit. The Reset Fix Board omits several connector pins from the wire-side connector and eliminates the PDB 5 volt connection to the MPU board. Instead, a new, reliable switched regulator circuit generates a stable 5 volt power supply that is used exclusively by the MPU board. This satisfies the watchdog circuit and the MPU board will not unnecessarily reset.

Other circuits in your pinball machine still use the original 5 volt power supply, so always replace failed capacitors, burnt connector pins, and bad rectifier diodes to keep this circuit healthy.