There could be several reasons why your roller shutter motor is not working. Some common causes include:

    Power source: Check the power source to ensure that the motor is properly connected and has a steady supply of electricity.

    Remote control: If the motor is controlled by a remote control, check the batteries or try a different remote control to make sure it's not the cause of the problem.

    Motor fuse: Check the motor fuse to see if it has blown and needs to be replaced.

    Control circuit: If the control circuit is faulty, the motor may not receive the signal to start and stop, or it may not receive the correct power and speed signals.

    Encoder: If the encoder is not functioning properly, the control circuit may not be able to accurately determine the position of the motor and control its movement.

    Gearbox: If the gearbox is damaged, the motor may not be able to transmit power to the electric roller shutter, and it may not move.

    Motor: If the motor is damaged, it may not be able to generate enough power to move the roller shutter.

These are some of the common causes of motor failure, and there may be other factors that contribute to the problem. To diagnose the issue, it's best to consult a professional or refer to the manufacturer's troubleshooting guide. If you're unsure about how to repair the motor, it's recommended that you seek the assistance of a trained technician to avoid potential injury or damage.