So my desktop pc (Custom built) Recently would turn on for about 30 seconds (No display comes through), and then would just shutdown. So I figured it might be the power supply. I replaced the power supply with a new 550 watt rosewill. And still it would not start. Im thinking it could be the motherboard or the processor, but the processor would usually give a beep code if im not mistaken? Im honestly stumped and don't want to buy a new motherboard and processor. Thanks in advance!