When a coil can be measured without unsoldering

Low-ohm coils such as pop bumpers read accurately in circuit. High-ohm coils such as hold relays may read low in circuit because lower-resistance coils are in parallel; free one lug before measuring.

Systems

• Electro-mechanical

Related tips

• Coil stops by maker
• Coil sleeves and plungers to keep
• Typical EM coil resistances
• EM coil voltage by maker
• Bally C0- coil numbers and their replacements
• Coil frame sizes by maker
• Keep a list of known coil resistances
• Rewinding an unobtainable coil onto its old frame

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