Pinball Coil Problems

The coils on pinball machines operate at 6 volts to more than 80 volts.

Some of the main reasons for pinball machine failures are malfunctions with coils. Problems can range from loose wires to magnetized parts. Due to the high voltage on some models, the repair person should be aware of potential dangers.

Common Problems

Coils should show specific behaviors at start-up and during operation of the pinball machine. The coil should pulse quickly at first and then more slowly during the game. Fuses need to be checked if the coil is not operating in this manner. If fuses check out as OK, the wires to the coils should be checked.

No Voltage

Both sides of the coil should have voltage slightly under 1 volt. A lack of voltage indicates a power problem. By following wires back from the coil, the operator may find a lost connection at another solenoid or other location. If power exists on both sides of the coil, devices that control coils are the most likely cause. Some systems may use as many as three transistor systems to control the coils.

Flipper Coils

Coil stops are metal bracket that hold the coil in place and stops the travel of the solenoid plunger. The coil's magnetic field may magnetize the coil stop and cause slow action by the solenoid. The best solution is to replace the magnetized coil stop.

References

• Pinball Heaven: Coil and lamp problems
• Pinball Medic: Electromechanical and Solid State Pinball Solenoid Coil Charts

Resources

• homepinballrepair.com: Introduction to Pinball Repairand Maintenance