The match number on a 1970s Williams no longer changes.

Williams 1970s match unit stops advancing

Cause: The small match stepper is driven by a relay whose armature carries a nylon lever that turns a nylon gear; the lever often breaks at the armature plate.

Checks

• Inspect the nylon lever and its joint to the armature plate.

Fix

• Replace the armature plate assembly (listed as WLL-A7989).

Systems

• Electro-mechanical

Related tips

• Bally 00-90 match unit
• EM match unit stuck on one number
• Bonus lights stop advancing and stay on one value: stepper unit plunger sticking
• What stepper units do in an EM
• Kinds of stepper unit
• Bally coin unit
• Gottlieb player unit
• How the EM match feature works and is disabled

Source: Repairing Electro-Mechanical (EM) Coin Operated Games to 1978, Part One, Clay Harrell (pinrepair.com)