Plug in the power connector and turn on the machine by depressing the rocker switch on the rear towards the line.

Does the red/green light on the front come on? If it does, your power supply is perfectly operational.

If the front lights do not come on at all this is generally an issue with the main board or the control board, which, in any case should be handled by the professionals who sell the printer. At this point you need to send in your printer for service. Sorry!