Possible Cause: 

1. The servo motor wire is not properly plugged in. 

2. The fixed lock block for XYZ shaft shipment has not been removed. 

3. Different zero lines of power supply lead to circuit failure.

Handling Method: 

1. Plug in the connection line of the drive motor. 

2. Remove the fixed blocks of each shaft. 

3. Use the multimeter to check the zero line breakpoint and connect.

4. Cut off the servo power supply and reset the machine after 1 minute of switching on the power.