[JD]

Are you sure it's the motor? I say this because most every mover I know of uses 2 phase stepper motors. The bigger problem is the drive chip. The usual symptom of a drive chip failure is that the motor kind of vibrates or quivers instead of rotating. If several of the motors are the same, you may be able to swap connectors and although things won't function correctly, you'll get an idea as to if the problem moves with the connector (chip) or stays with the motor. Just a thought.