So after moving it back home from college, my computer refuses to stay on. It was working fine before the move, we didn't drop it during the move, and after the move, when the power button is pressed, it shuts off after roughly 4 seconds. Everything sounds normal up until it just shuts off.
Things I've tried:
1. Switching out memory sticks since I have another pair that I thought was dying.
2. Switching out hard drive (inadvertently breaking something) just to check/narrow down that component.
3. Swapping out the video card/unplugging it completely. While unplugging it completely doesn't shut off the computer after 4 seconds, it beeps for a second or two and then nothing. I assume it's complaining about lack of graphics card. The old one, same deal.
4. Swapping out power supply for another one. Also to no avail.
5. Changing CMOS battery. Wanted to reset CMOS and wasn't sure if pins were working so opted for the more ghetto way, tested the battery and found it was dead, replaced, but same deal.
Everything I've looked up suggests overheating, but it's freaking cold and it's cleaned inside so... probably not it, especially since it was working before with no problems.
Any ideas? My guess is CPU and/or mobo. I ordered replacement ones already, but if the problem can still be fixed, I can leave this comp for my dad.