Err9 alarm of Z axis

The Z axis Err9 alarm appeared during machining, turn off the machine power then restart, the machine can work for a while, then the Err9 come again.

The voltages, mechanical parts are fine, change the servo motor and driver, but the problem still exist.

Check carefully the servo motor encoder cable and found out it was broken a little bit, this is the reason of the problem, change it and then the machine resume to work.