Computer shutting down randomly.

JLawrence85

Honorable
Sep 1, 2012
15
0
10,510
I have a homebuilt PC that I use for casual gaming that's been fine until last week when it began shutting down randomly. It could go for hours or days without issue or it could shut down every 15 minutes. It would shut down during virus scans specifically and it would shut down when I tried installing Guild Wars 2. I couldn't figure it out so I took it to a local PC repair place who said they ran virus scans fine and installed/played the game without any issues, but somehow they were able to determine my HDD with Windows 7 was failing and that was the problem. So I bought a new HDD and did a fresh Windows install, played Guild Wars 2 for a little while and then it shut down again. This would also happen when just web browsing but seemed more frequent during gaming.

Cooler Master HAF 932 case
CPU: Intel Core 2 Quad 2.4GHz
MoBo: Gigabyte P45T-ES3G
RAM: 8GB DDR3 G.Skill
GPU: GeForce GTX 460
PSU: Corsair HX750w modular
HDD: a 750gb Seagate SATA and a 500gb Seagate SATA (brand new)

I have no idea what to do! Buying diagnostics and replacing the allegedly failing hardware did not solve my problem. Any ideas?
 

JLawrence85

Honorable
Sep 1, 2012
15
0
10,510
Using CPUID: Hardware Monitor, my CPU is desktop idling at 180-212 degrees Fahrenheit. My GPU is at 100 degrees. Not sure if those temps are good or bad, but I can't fathom another way to add cooling to this case. There's 4 gigantic fans all working fine.
 

JLawrence85

Honorable
Sep 1, 2012
15
0
10,510
I did. No change. Also tried my old core2duo wolfdale which never gave me problems and it still ran close to the same temperature. All fans are running. Heatsink is seated properly.
 

JLawrence85

Honorable
Sep 1, 2012
15
0
10,510
I don't. It was a Gigabyte, older model.

Important update on this: Yesterday it froze at the desktop and I had to hard shut down and then Windows did a disk read error. Keyboard didn't work in BIOS. Eventually it started freezing in BIOS, CMOS and safe mode. It gradually would last longer before freezing and I was able to get to my desktop and open Firefox before it froze again and I haven't touched it since.

Everything looked fine, PSU and GPU are brand new. RAM and MOBO are fairly new. CPU's are both older 2.2-2.4ghz socket 775. For lack of any other ideas, I ordered a new CPU and MOBO:

ASUS M4N98TD EVO AM3 NVIDIA nForce 980a SLI ATX AMD:http://www.newegg.com/Product/Product.aspx?Item=N82E16813131636

AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core: http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727

Hopefully after these it will run fine, or I just bought a new MOBO, CPU and HDD for no reason. :(