How System 3 audit mode looks

System 3 (white flipper ROMs) shows no software ID. When its audits come up, the credit window holds the audit number and the ball-in-play window shows "04", swapped compared with later systems, and player 1 shows the value. Setting the manual-down/auto-up switch to auto-up makes it cycle through the audits on its own. Adjustments are made on DIP switches.

Systems

• Williams System 3

Related tips

• System 3 audit mode looks different
• Identifying a System 3 to 7 CPU board
• Audit mode with good battery voltage
• Which System 3 to 7 games use which flipper ROM system
• A System 7 CPU board can run any System 3 to 7 game
• System 3-6 SW1 test results
• System 3 with no batteries boots into audit mode
• Chips that commonly fail on System 3-7 boards

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