System 9: Sorcerer uses two game EPROMs, Comet and Space Shuttle one

Sorcerer runs two game EPROMs, while Comet and Space Shuttle use one larger one, so a System 9 CPU board is jumpered differently for Sorcerer. Check the jumpers when moving a board between these games. The test EPROM at U20 works with either setting.

Systems

• Williams System 9

Games

• Comet
• Sorcerer
• Space Shuttle

Related tips

• System 9 CPU and sound test EPROMs
• Which System 11 CPU boards fit which games
• System 9 and System 11 seven-segment LED codes
• System 9: right flipper on at power-up and LED code 7
• Starts in the service menu at every power-up: broken battery connection
• Lamp column 1 stuck at full brightness after a MOSFET mod: bad pre-driver Q15
• Whole switch column dead and board fails the jumper test: column transistor
• System 9 versus System 11 display data

Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Two, Clay Harrell (pinrepair.com)