A pre-WPC-S CPU board never boots with a larger game ROM fitted.

CPU board from an early game won't boot: ROM jumper W1

Cause: Boards from Funhouse, Bride of Pinbot or Harley Davidson may have jumper W1 set for a 1 meg ROM at U6; every other game uses 2, 4 or 8 meg ROMs.

Checks

• Check the W1 setting before any repair.

Fix

• Set W1 for the ROM size fitted.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS

Games

• Funhouse
• Harley Davidson
• The Machine: Bride of Pinbot

Related tips

• Pre-WPC-S CPU EPROM size jumpers W1 and W2
• Country jumpers W13 to W18 on pre-WPC-S CPU boards
• Dead CPU: no clock signal at the 6809
• What is on the WPC CPU board
• Dead CPU: check the reset and IRQ lines
• What fails on a WPC CPU board
• Why coils stay off until the CPU boots
• Running a WPC CPU board on the bench

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Three, Clay Harrell (pinrepair.com)