The Hidden Treasure in Cheltenham Today’s job took me to Cheltenham to look at the best-selling pinball machine of all time: The Addams Family. The owner had purchased it over 20 years ago for a fraction of today’s value and didn’t realize he had a serious collector’s piece sitting in his home.
The Symptoms The machine hadn’t been played in a long time. When they tried to fire it up for the weekend, they got the dreaded “Factory Settings Restored” message, and the coin door buttons (Enter/Up/Down) were completely unresponsive.
The Diagnosis: The “Silent Killer” “Factory Settings” usually means dead AA batteries. When I opened the backbox, I was initially relieved to see a remote battery holder installed. I thought, “Great, maybe just dead batteries.”
However, a closer inspection revealed the truth. Alkaline corrosion from old batteries (likely removed years ago) had never been neutralized. It had slowly eaten away at the PCB traces, specifically attacking the chip responsible for the Direct Switch Matrix (which explains why the door buttons failed). The green death had even climbed up the legs of the EPROM.
Lesson: Just adding a remote battery holder isn’t enough. You must neutralize and repair the existing corrosion, or it will continue to spread like a cancer.
The Electronic Overhaul
- CPU Swap: Instead of attempting a patchy field repair, I installed a clean, fully rebuilt CPU board to guarantee reliability.
- Voltage Issues (The 5V Line): With the new CPU in, the game booted, but I checked the test points. The 5V logic rail was sitting at 4.8V. On WPC machines, anything below 4.9V is a recipe for random resets.
- Driver Board Repair: I removed the Power Driver Board and replaced the capacitors for the 5V and 12V circuits. I found the 12V capacitor had also leaked electrolyte onto the board. I neutralized the area and installed fresh, high-quality caps.
The Result
- Logic voltage is now a rock-solid 5.1V.
- I installed LEDs in the backbox to reduce heat and stress on the General Illumination (GI) connectors (which were already showing signs of burning).
- Full playfield detail, cleaning, and new rubbers.
The owner was thrilled to see his investment back from the dead. This Addams Family is now ready for another 20 years of “Mamushka”!