System 3 with no batteries boots into audit mode

A System 3 (white flipper ROM) CPU board without batteries tends to come up in audit mode, often showing "01 04" or "18 04", and counts up the audits if the coin door switch is on auto-up. Good batteries make the tests easier to reach. White flipper ROM tests also run noticeably slower than later ones.

Systems

• Williams System 3

Related tips

• Audit mode with under 3.6 V at the RAM
• Game powers up in audit mode
• Battery holder looks fine but makes no contact
• How System 3 audit mode looks
• Move the CPU batteries off the board
• CPU will not boot after battery corrosion
• Replace batteries of unknown age right away
• System 3 audit mode looks different

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