Guide To EM Score Reels and Steppers
– Cleaning and Fixing

Introduction

EM score reels and steppers may get the most use of any component in the pinball machine.  Since they are used the most, keeping them working maybe the most important part of maintaining an EM pinball machine.

The single most common game error is that the game will not start up, and the score motor (or score wheel) in the cabinet keeps spinning.  A newbie then attacks the score motor which is the wrong first step.  Frequently, the cause is that a score reel will not return to zero, or the zero sensor switch is not working.  

Supplies Needed:

• Small screwdrivers – typically slotted and Phillips
• Dremel or similar
• Dremel polishing wheel 
• 1/8″ Carbon Steel Brush 443 for Dremel
• Dremel Sanding Brush Wheel (flap wheel)
• 91% Isopropyl Alcohol.  Not rubbing alcohol.  Higher than 91% is not needed.
• Q-tips
• Pinball Switch Adjustment Tool
• Nut Drivers – typically English measurement
• Soldering iron (35 watt pencil) or soldering station temperature controlled – B style smaller chisel tip suggested – might not be needed, but important to have.
• Lead / tin solder.
• Finish Line Dry Bicycle Chain Lubricant.  Typically 8 oz.
• Mothers Mag & Aluminum Polish.  Typically 10 oz.
• Teflon Grease or Super Lube.  A 4 oz tube will last a long time.  16 oz will last forever.
• Old muffin tin or similar to hold the parts as they are disassembled.
• Light sewing machine oil.  One with a long ‘spout’ is preferred.  Useful when grease is not appropriate.

Supplies Suggested:

• Container for parts.  Plastic cup, muffin tin, or magnetic cup
• Alligator test leads – clip leads
• Light stand / additional light source
• Voltmeter / DVM
• Microfiber Towels
• New coil sleeve (see pinball parts providers).  It is better to have new ones but it is sometimes possible to clean them if you are lucky and they are not damaged. 

Types of Score Reels

Although all score reels perform the same function, keep score by moving the reel, the different manufacturers have slightly different designs.  Therefore, we shall cover them individually.

Gottlieb Score Reels

Learn to disassemble, clean up all those parts, then reassemble to make your Gottlieb score reels really snap into position.

Williams Score Reels

Learn to disassemble, clean up all those parts, then reassemble your Williams EM score reels. 

Instructions for newer Williams score reels from the 1970’s. 

Instructions for earlier older 5″ Williams score reels.

Stepper Mechanisms

Steppers are not score reels, but cleaning and adjusting them is similar.