Check if the start button wire connector is dropped, whether the start button is damaged, check whether the start button is energized, and measure the resistance value with a universal meter (the pointer of the universal meter does not move, the movement indicates normal).
If the motor is missing, check if the three-phase power is normal.
There is also a kind of rocker arm cutting machine that installs a thermal relay. Check if the thermal relay protection jumps out. If it is pressed out and then turned on again, please replace the thermal relay if it is not useful.