After fresh batteries are fitted the game shows ADJUST FAILURE at every power-up. A factory reset lets you play, but settings are lost again once it is switched off.

'ADJUST FAILURE' every time it powers on: battery corrosion on the CPU board

Cause: Old alkaline battery leakage had corroded the board near the battery holder (here the legs of chip U41), so the memory was not kept powered.

Checks

• Remove the batteries and inspect the holder and nearby chip legs with a light for white or green corrosion.
• Look further along the board; the damage can spread under chips.

Fix

• Remove the CPU board and neutralize the corrosion with white vinegar and a brush, rinse with distilled water and dry fully before powering up.
• Replace any parts the corrosion has destroyed.
• Fit a remote battery holder (or NVRAM) so batteries never sit on the board again.

Battery leakage is caustic: wear gloves and eye protection, and keep it off skin.

Systems

• Williams System 11C

Games

• Whirlwind

Related tips

• "Factory Setting" or "Adjustment Failure" at power-on
• Settings lost although the batteries are good (blocking diode D2)
• New CPU batteries go flat quickly
• "Factory Setting" or "Adjustment Error" at power-on
• Changing the CPU batteries without losing settings
• Checking the battery holder voltages on the CPU board
• Cleaning up battery leakage on the CPU board
• Better battery holder for System 11 CPU boards

Source: Pinball Repair help group!! (Facebook group)