In most cases, this might be caused by a faulty motor driver board. Troubleshoot by the steps below.

Remove the bottom plate (as shown).

1. Check the status of the indicator light on the motor driver board.
2. If the indicator light is not on, measure the voltage of the power input of the board (as shown).
3. If the plug reads 24V, the board is faulty. Replace it with a new, identical one.