Starting maybe a month or even longer ago, my computer would randomly shut off. I hadn't recently installed any hardware/software (to my knowledge). Sometimes I could go a whole day without it shutting off, some days I couldn't even go 10 minutes. I noticed that sometimes the computer would just shut off, and sometimes it would simply freeze up and make a long beep, at which point i would just hit the reset button. I also noticed that if i stood up too fast it would shut off, but sometimes i could jump around in my room and nothing would happen. Sometimes it would also just shut off even if I wasn't moving.
Also, after shutting off, one of three things would happen:
1) I would simply need to press the power button again for it to turn back on and it would boot back up like nothing happened
2) It would say windows failed to load properly and give me options to run in Safe Mode, Last Known Good Settings, or Start Normally
3) It would say "Overclocking Failed", at which point i would enter bios and assure that all of my devices were actually not overclocked, and then continue to boot windows normally
After these messages, I expected that my computer was overheating, but upon checking Asus Probe, all of my fans were running properly and my temperatures were at normal conditions. After this, I suspected a virus, but my daily AVG scans showed nothing and Hijack This showed nothing as well. Then, my computer started to turn off even before windows could boot.
I have tried the following things in this order:
1) Cleaning fans and case
2)Replacing Power Supply
3) Booting without hard drive
4)Booting without graphics card (resulted in a beep and the computer didnt shut off afterwards, however i had no monitor and couldn't tell what was going on)
5) Replacing graphics card
6) Swapping RAM to different slots
7) Replacing Processor
After all of this, my computer still does not work. The only thing I have in mind is replacing my motherboard, but my motherboard is old and hard to find in stores (Socket 478, AGP, and other bad stuff). It would be a pain to order one online and have not work, only to have to return it and pay restocking fees. So my question to you is: is replacing the motherboard what will solve my problem? and, if not, what will?
Thanks in advance, and sorry again if this is the wrong place to post this.