Cleaning up alkaline battery leakage on a CPU board

Steps

• Remove the leaking batteries. White crust under them means the holder, nearby chips and sockets are likely damaged.
• Remove the battery holder and any corroded chips and sockets.
• Wash the area with a 50/50 mix of water and white vinegar to neutralise the alkaline residue, then rinse with water and dry.
• Sand corroded areas back to bare copper.
• Fit new components. Skipping the vinegar wash lets the corrosion return.

Battery leakage is caustic; wear gloves and eye protection.

Systems

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

Related tips

• Switch matrix row fails with good switches and diodes: battery-damaged CPU board
• Changing the CPU batteries without losing settings
• Batteries get hot with the game on
• Battery power not reaching the RAM: diode D2
• Settings lost because battery voltage at the RAM is too low
• Coin door Begin Test button does nothing: acid-broken trace on the CPU board
• "Factory Setting" or "Adjustment Failure" at power-on
• "Factory Settings Restored" every power-on

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