What the thread found

• A follow focus motor that worked normally throughout a long production day began spinning rapidly at maximum speed and jammed against the lens end stop near the end of the shift, with the motor continuing to spin even when disengaged.
• The motor felt unusually warm to the touch when the malfunction occurred.
• A technician inspection found no fault and the system worked perfectly during testing.
• The most common cause of this type of motor behavior is a faulty motor cable or a poor connection at either the motor or control unit connector.
• A partially disconnected or pushed-in motor cable can cause the motor to spin at full speed uncontrollably.
• Testing the motor with a different cable, or moving the motor to a different channel on the control unit, can help identify whether the fault is in the motor, cable, or connector.
• Physical impact or vibration during heavy use may have caused the cable or connector to develop a fault in signal transmission while power still reaches the motor.

Depends on

• The fault could not be replicated during professional service testing.
• The operator did not confirm whether alternative cables or connectors were tested to isolate the problem.
• It is unclear whether the motor was used after the malfunction occurred or if the issue resolved itself.

Parts

Follow Focus

Same gear or parts

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