Okay so I'm back again. My PC is still doing this.
It's completely random, sometimes it'll stay on all day, sometimes it'll turn off before windows loads, sometimes it'll turn off after 15-20 minutes. It seems to turn off whenever I need it the most

Today, it wont even start. The fans will spin a 1/4 turn and thats it. I have to unplug or turn off the power supply and then wait for the light on my motherboard to turn off, and then switch power back on for it to try to start again. All it will do is spin the fans a 1/4 turn.
I thought maybe it was a grounding issue so I took the parts out of the case and set them on some cardboard. Same thing.
The PSU in my computer is good for sure. What do you think...motherboard dead?