My computer refuses to boot or POST. It was working fine a couple nights ago and the day after, pressing the power switch just caused the fans to spin for a second and stopped. So far I have tested the motherboard without the RAM, tested the power switch, and tested the power supply. The speaker will not beep at all. I did this all yesterday and gave up. In the middle of the night, I woke up to find the computer running. All the fans were on apart from the GPU, which was not running as there was no video output. I was able to shut off and turn on my computer and my motherboard beeped each time. I have no clue what caused it to turn on, nobody had touched it. It was very early in the morning so I shut off my computer and went back to sleep. I woke up this morning and had the same problem as earlier. At this point, I am worried it is either the motherboard or the CPU, but I don't know which and I have no compatible alternate parts. Is there a way for me to figure out if it's the CPU or the motherboard is faulty? I ran power through the CPU fan to see if it was working and it was, so I don't believe it overheated. I don't want to spend money on one without knowing which is faulty. Also pardon my ignorance on the matter, I'm not the best when it comes to building computers but I am trying to learn. Thank you.