Analysis on 960 not powering on
Measure the voltage between LI and N1, L2 and N2, L3 and N3, respectively. They should all be AC 123V.

Measure the voltage at the motherboardAC9V

After the machine presses the ON button, the governor switch is turned on, and the mesh belt is rotated. Does the machine cooling fan work?
If the above is normal and the display does not work, it may be a problem with the main control board.

960 circuit diagram ref.