Computer shutting itself down

[asfcobra]

First and foremost, I'd like to briefly introduce myself. I'm Jon, and I was recommended to these forums by a friend of mine. I am having some issues with my computer, and I am in dire need for some help. I'm not particularly an amateur, I have a decent amount of experience with computers, but this issue is just irritating me to no end. Occasionally I find myself playing PC titles like ArmA 2 or Team Fortress 2, even some older games like Fahrenheit. The issue is, during game, at no random timed interval, my computer will literally shut off instantaneously. Sometimes it will occur, other times I will be lucky enough for it to not happen. The key is, once everything shuts off at once, I try to turn on my computer with the power button to no avail. In order to actually start my computer back up, I have to unplug the power supply unit, hit the switch on it, wait until I hear this noise that sounds like the psu is actually totally off. Plug it in, switch it on, and then hit the power button. From there everything works fine. No yellow light on the power supply confuses me, as I am told this would be a sign of power failure. Atop that, I don't think it is heating issues either, I will post my specs below if it will help.

Thanks.

Also, it should be noted that I'm using Everest Ultimate Edition, and I have ran harddrive tests, cpu tests, and memory tests for 10 minutes, none of which have caused this issue to occur. I have also reformatted twice since it began a few months ago. And before I was having an issue where my oldest harddrive was shutting itself off, so I eventually removed it.

--------[ Summary ]-----------------------------------------------------------------------------------------------------

Computer:
Computer Type ACPI x64-based PC
Operating System Microsoft Windows 7 Home Premium
OS Service Pack Service Pack 1
Internet Explorer 9.0.8112.16421
DirectX DirectX 11.0
Computer Name JON-PC
User Name Jon
Logon Domain Jon-PC
Date / Time 2011-08-15 / 23:24

Motherboard:
CPU Type TripleCore AMD Phenom X3 Black Edition 8750, 2326 MHz (12 x 194)
Motherboard Name Gigabyte GA-MA785G-UD3H (2 PCI, 3 PCI-E x1, 2 PCI-E x16, 4 DDR2 DIMM, Audio, Video, Gigabit LAN, IEEE-1394)
Motherboard Chipset AMD 785G, AMD K10
System Memory 4096 MB (DDR2-800 DDR2 SDRAM)
DIMM1: Corsair XMS2 DHX CM2X2048-6400C5DHX 2 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-13 @ 270 MHz)
DIMM2: Corsair XMS2 DHX CM2X2048-6400C5DHX 2 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-13 @ 270 MHz)
BIOS Type Award Modular (09/16/09)
Communication Port Communications Port (COM1)
Communication Port Printer Port (LPT1)

Display:
Video Adapter NVIDIA GeForce 9800 GTX/9800 GTX+ (512 MB)
Video Adapter NVIDIA GeForce 9800 GTX/9800 GTX+ (512 MB)
3D Accelerator nVIDIA GeForce 9800 GTX
Monitor Dell E178FP [17" LCD] (G248H876787S)

Multimedia:
Audio Adapter Realtek ALC889A @ ATI SB750 - High Definition Audio Controller

Storage:
IDE Controller Standard Dual Channel PCI IDE Controller
IDE Controller Standard Dual Channel PCI IDE Controller
Floppy Drive Floppy disk drive
Disk Drive HDS728080PLAT20 ATA Device (80 GB, 7200 RPM, Ultra-ATA/133)
Disk Drive ST3500320AS ATA Device (500 GB, 7200 RPM, SATA-II)
Optical Drive DTSOFT Virtual CdRom Device
Optical Drive LITE-ON COMBO SOHC-4836K ATA Device (DVD:16x, CD:48x/32x/48x DVD-ROM/CD-RW)
SMART Hard Disks Status OK

Partitions:
C: (NTFS) 76316 MB (35560 MB free)
E: (NTFS) 465.7 GB (377.1 GB free)
Total Size 540.3 GB (411.8 GB free)

Input:
Keyboard HID Keyboard Device
Mouse HID-compliant mouse
Mouse Logitech USB Cordless Mouse

Network:
Primary IP Address 192.168.1.49
Primary MAC Address 6C-F0-49-04-23-76
Network Adapter Realtek RTL8168C(P)/8111C(P) Family PCI-E Gigabit Ethernet NIC (NDIS 6.20) (192.168.1.49)
Network Adapter TAP-Win32 Adapter V9 (Tunngle)

Peripherals:
Printer Fax
Printer Microsoft XPS Document Writer
Printer Send To OneNote 2010
FireWire Controller Texas Instruments TSB43AB23 1394A-2000 OHCI PHY/Link-Layer Controller (PHY: TI TSB43AB23)
USB1 Controller ATI SB750 - OHCI USB Controller
USB1 Controller ATI SB750 - OHCI USB Controller
USB1 Controller ATI SB750 - OHCI USB Controller
USB1 Controller ATI SB750 - OHCI USB Controller
USB1 Controller ATI SB750 - OHCI USB Controller
USB2 Controller ATI SB750 - EHCI USB 2.0 Controller
USB2 Controller ATI SB750 - EHCI USB 2.0 Controller
USB Device Logitech USB Camera (Webcam Pro 9000)
USB Device Logitech USB Cordless Mouse
USB Device Logitech Webcam Pro 9000
USB Device USB Composite Device
USB Device USB Input Device
USB Device USB Input Device
USB Device USB Input Device
USB Device Webcam Pro 9000

DMI:
DMI BIOS Vendor Award Software International, Inc.
DMI BIOS Version F4
DMI System Manufacturer Gigabyte Technology Co., Ltd.
DMI System Product GA-MA785G-UD3H
DMI System Version
DMI System Serial Number
DMI System UUID 36434630-34393034-32333736-FFFFFFFF
DMI Motherboard Manufacturer Gigabyte Technology Co., Ltd.
DMI Motherboard Product GA-MA785G-UD3H
DMI Motherboard Version x.x
DMI Motherboard Serial Number
DMI Chassis Manufacturer Gigabyte Technology Co., Ltd.
DMI Chassis Version
DMI Chassis Serial Number
DMI Chassis Asset Tag
DMI Chassis Type Desktop Case
DMI Total / Free Memory Sockets 4 / 2

 

[MindoverMaster]

Get yourself a new PSU. What brand and wattage do you have?

Edit: Welcome to TF!

 

[asfcobra]

Thanks for the welcome and quick reply MindoverMaster, according to what the label says, it's a Coolmax Cu-700b.

It probably isn't the best out there, I've had it for quite a while, ever since I've upgraded this computer a year or two again maybe. But it's held for quite a while. And it never seems to shut down on idle, only when I play games. My girlfriend and I have done several skype calls over night and I never had any issues.

Sorry for the double post, also, I've noticed that my CPU clock (according to Everest) is fluctuating from 1.1 GHz to 2.39 GHz, where as stock I think is 2.4. I had overclocked previously in the past, but I eventually set it all right back to stock settings, letting the motherboard automatically set it back. What's up there?

**Update**
Upon attempting to even run FurMark GPu test at my native resolution 1280 x 1024, my computer instantaneously shuts itself down as usual. GPU issue?

 

[C0RR0SIVE]

Not a GPU issue, a GPU that overheats instantly, will just cause a serious lockup. A GPU that stresses your PSU, can cause the PSU to power off to prevent damage.

 

[Slaymate]

I'm voting on a bad power supply.

 

[asfcobra]

Okay, so we can rule out GPU probably. Could it be not enough power getting to the gpu?

 

[Slaymate]

It could be shutting downbecause the gpu (or any other component) is overloading the power supply, the power supply could be getting hot and shutting down, or it could be the CPU getting hot and shutting down.

The gpu could be the problem but normally you'll get artifacts and/or tearing or it will just crash to the Desktop. The system just shutting down is usually a power or cpu overheating problem.

 

[asfcobra]

Okay, that makes sense. So what would you suggest be my next course of action to rule out the real issue? Should I check my temps on my cpu or what?

 

[MindoverMaster]

Get HWMonitor, and post a screenshot.

 

[patonb]

It actually sounds like youre tripping the power supply either thermally or electrically.

Carefully feel the power supply to see if its hot. Also see if it all covered in dust and he fans spinning.

The only good way to test is with a multimeter. If you can get ahold of one of them, you can test the psu.