Keep a list of known coil resistances

Coils fail when heat burns the enamel and turns short together, lowering resistance and upsetting the magnetic field even before the reading drops below 2 ohms. Keeping a written table of frequently used coil numbers with their ohms lets you check a doubtful coil quickly; failing that, compare with the same coil used elsewhere in the game.

Systems

• Electro-mechanical

Related tips

• Typical EM coil resistances
• Normal EM coil resistance range
• Gottlieb EM coil windings, resistance and wrapper colour
• Coil stops by maker
• Coil sleeves and plungers to keep
• EM coil voltage by maker
• What makes a coil stronger or weaker
• Bally C0- coil numbers and their replacements

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