That is, probably, a sign that ESD has ruined the electronics that accepts the signals over V5 wires.
If you can rule out mechanical problems with the inner motor by gently spinning it or running it directly with a 9V battery, then it is definitely the electronics.
If the inner motor is fine - you can use it as a spare. But if the motor is stuck then you can try to plug a working inner motor into the board, but I doubt that it will help, since the board already fails to communicate with brain.