Game boots into audit mode.

Audit mode with under 3.6 V at the RAM

Cause: IC19 pin 22 below 3.6 VDC: dead batteries, bad holder, bad D17, a broken trace or a bad IC19 socket.

Checks

• Measure IC19 pin 22 (bottom left, opposite pin 1); new batteries give about 4 V.
• Trace the voltage back through D17 to the holder.

Fix

• Repair whichever link is broken.

Systems

• Williams System 3
• Williams System 4
• Williams System 6 / 6A
• Williams System 7

Related tips

• System 3 with no batteries boots into audit mode
• Game powers up in audit mode
• Battery holder looks fine but makes no contact
• CPU will not boot after battery corrosion
• Boots straight into the adjustments menu: corroded battery holder
• Lights up but dead after storage: leaked batteries on the board
• Replace batteries of unknown age right away
• Clean battery corrosion off a CPU board

Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part One, Clay Harrell (pinrepair.com)