The fan can be started, indicating that the power supply is ok, but the failure to self-check should be the problem of the motherboard. Since you have not entered the self-check, of course, you can't redo the system. There is a big problem with the motherboard. Can you see if your motherboard has expired first? Then find dealers, computer hospitals and technology markets to do motherboard testing. Generally speaking, the processor has strong vitality and will not be damaged.