Stepper cleaning, part 4: refit and test

Steps

• Hold the cog shaft so it cannot unwind and push the wiper disc back on; refit the screw or nut without over-tightening, lining up your marks.
• Fire the advance coil by hand, then reset (or step down) the unit; it should return cleanly.
• Use only enough clock spring tension to reset the unit; more makes the advance coil struggle.

Systems

• Electro-mechanical

Related tips

• Stepper cleaning, part 1: mark, check and remove the wipers
• Stepper cleaning, part 2: free a seized shaft
• Cleaning and aligning an EM stepper unit
• What stepper units do in an EM
• Kinds of stepper unit
• Faults that point to a stepper unit
• Set stepper wiper finger tension and alignment
• Gottlieb AS relay (miniature match stepper)

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