Computer is randomly shutting down

[Kane2553]

I have been having an issue with my computer shutting down for some time now. It happens randomly and when i go and restart the computer it will start up with the fan running wide open and shut down. I can keep restarting 5 or 6 times and it will eventually boot up just fine and work for several day before it acts up again. I have done the typical trouble shooting, taking one component out at a time and restarting. I was positive it was the MOBO because when i took it out the heatsink on one of the bridges was hard as a rock and fell in the floor. So i decided to replace the MOBO and processor. It is till doing the same exact thing. I am at the end of my rope with this computer. Please help.
My setup is
Brand new Cooler Master HAF-912
Brand new EVGA SuperNOVA 750 Bronze PSU
Brand new AMD FX-8350 Black Edition
Brand new ASUS Sabertooth 990FX R2.0
Cooler Master Liquid cooler
2 120 mm case fans
3 sticks of DDR3 8 gb Patriot RAM
ATI Radeon HD 5450
Brand new Windows XP Install

 

[Vic 40]

If two sticks of that ram are from the same package and the third isn't take that third one out and see what it does.

 

[Kane2553]

I have switched out all three sticks of ram and still doing the same thing. The odd thing is it will run fine then the next time you start it it may not work until youve restarted a dozen times then its fine again.

 

[Vic 40]

Do you have issue when in the bios? There is a pretty recent bios,do you have that?

SABERTOOTH 990FX R2.0 BIOS 2901
Improve system stability
from 2016/08/05

Only install when the system starts/works normally. The board has Asus "usb bios flashback" (google! or read the manual) so if an update fails should that give the option to reflash the bios.Can use it to update the bios aswell.

 

[Kane2553]

The bios I have is 2501. What came with the mobo. I'm guessing that could be an issues.

 

[Vic 40]

Update the bios and see if it helps.

 

[Kane2553]

Updating the bios did not help.

 

[Vic 40]

Can you test with another psu? Maybe from a friend or ...

 

[Kane2553]

It was doing it with my old computer as well. This PSU is new and its still doing it. The only thing thats not new on this computer is the sound card, video card, RAM, and Coolermaster everything else is brand new. I have switched out all the older pieces and still cant narrow it down.

 

[Vic 40]

Can you test with another gpu?

 

[Kane2553]

Would the GPU or Sound Card be causing this? Ive not seen any graphics issues when it actually comes on. I honestly think its getting worse. It wouldn't even POST then after 15-20 times powering it up it came on no problem.

 

[Vic 40]

Since it seems to be one of the old parts is it wise to elimate one by one.I would also take the soundcard out as a test and see if that gives issues.