"Factory Settings Restored" keeps appearing after new batteries are fitted.

New batteries but still losing settings: test the holder

Cause: Corroded battery holder contacts. The contacts are rivets whose heads can corrode through and drop off.

Checks

• Game off, black lead on ground (ground strap, a CPU board screw or the bottom-left battery terminal).
• Red lead on each battery's positive solder point from left to right: about 1.5, 3.0 and 4.5 V.

Fix

• Replace the holder. The black plastic holder from WPC-S and later games, A-15814, is the best one for any WPC game.
• A remote holder is a good alternative.

Systems

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

Related tips

• Battery holder looks fine but makes no contact
• Replacement battery holder for the CPU board
• "Factory Settings Restored" every power-on
• New batteries die in weeks or settings still lost: U8 RAM
• Better battery holder for System 11 CPU boards
• "Factory Settings Restored" at power-on
• Battery power not reaching the RAM: diode D2
• "Factory Setting" or "Adjustment Failure" at power-on

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