The screen does not start without switching on the power supply - what is dying?

Question

Iron

The computer starts to spin the fans on the processor, vidyuhi, and so on, but there is no picture, there is no power to the usb. Last time I turned off the card reader and it turned on normally, now everything is the same. Who is dying: the power supply or the mother?

Answer 1

More information would be needed: what kind of mother, what kind of power supply, otherwise the telepath on duty is on vacation.