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All of a sudden, my Windows 7 PC has started to suddenly reboot without warning shortly after starting up a game, and I'm curious if I should suspect the video card or the power supply being at fault. Oddly, after turning off the automatic reboot option in Window's Startup and Recovery options, I don't see a true blue screen of death when this happens. Instead, my screen goes black, and my system seems to hang.

The full details:

I played games for a few hours yesterday with no problem. Towards the end of the day, I upgraded my Nvidia drivers from 360.97 to 310.90. After another 30 or so minutes of gaming, I had no problem. This morning, however, I can't load up a game for more than a minute before it causes my screen to go black (again, it was automatically rebooting at this point until I set Windows to stop doing that).

(I had a similar situation about a month ago, where I started getting graphical artifacts in my games for a a few minutes before my system would in fact get a true BSOD, which indicated an issue with the video driver. After a few days of this, the card permanently died, and I couldn't get any video output from it. I RMA-ed the card to MSI, who sent me a replacement. Everything seemed fine until today.)

Initially thinking that the driver update last night started the problems, I did a system restore back a few days to version 360.97. I saw the same black out/system hang behavior still, so I did a clean reinstall of the drivers, only to see the same issue still occur. So, I'm wondering now if I've managed to burn out yet another video card, or if this is a sign of something different - say, my power supply unit slowly going bad and not being able to provide enough power to my system when my video card starts kicking into gear. It seems too soon for the replacement video card to be going bad too.

Is there any way I can tell what might be going wrong for sure? Without a true blue screen appearing, I can't tell what it is that is failing.

Here are my general system specs: Windows 7 Pro x64, ASRock Z68 Extreme4 Gen3 motherboard, Intel i5-2500K CPU, 16 GB RAM, MSI GTX 560 Ti video card, OCZ 500W PSU (I can't remember how old the PSU component is, though I'd guess at least 3-4 years)

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Your board has built in HDMI correct? Have you tried bypassing the card and use the onboard port just to see. You RMA's one card, it could be a bad replacment. New stuff in not always as it should be and could be defective. – Carl B Jan 11 '13 at 22:35
up vote 1 down vote accepted

Try to run a pass of memtest86 to rule out your memory. This is the most likely component to have a defect and cause freezes like this.

Check your temps and make sure you're no higher than 60-70 deg C for a CPU and 80-90 deg C for a GPU.

Did you OC the card? Try turning it down to defaults to see if it continues.

Additionally, check the mobo for puffy capacitors, and see if you can peek into the grille of the PSU with a flashlight and check for the same (I wouldn't advise opening it, however). If you have another spare PSU around, try swapping it out to see if the issue still occurs.

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Great tips, thanks. Unfortunately, I can't for the life of me get memtest86 working on a bootable USB drive, even using the usb auto-installer at Regardless, though, I may have found the problem. I don't overclock anything in my system, temps seem to be fine (around 30-40C for both CPU and GPU), and no obvious issues with my mobo. (continued below) – Derek Jan 11 '13 at 22:55
However, what I did notice is that I have two case fans connected to the power line in front of one of the two leads connected to my Nvidia card. I suspect, since they came with my case some 6-7 years ago (just about every other part has been upgraded or replaced since then), that one of them is failing and not providing enough power to my video card. If I continue to not have issues with the fans out of the way, I probably have located my problem. Since your tips answer my original question, I'm marking this the best answer. – Derek Jan 11 '13 at 22:58
Possible, but not likely. I doubt it would be a short in one of the fans, unless you nicked one of the wires. Blank CDs are cheap, I'd recommend burning a copy of memtest. – Bigbio2002 Jan 11 '13 at 23:16
Then, if nothing else, I may have had a loose power connection to my videocard, and separating and reconnecting the cables may have fixed that (I also since plugged an extra power cable directly from my modular PSU to the videocard - no issues since). As for memtest, I haven't had a working CD/DVD drive in my system since swapping out mobos a couple years back and realizing I only had IDE disc drives and only SATA connections on my new board. Ever since then, if I need to reboot from external media, I just use a USB drive now. I'll see if I can still get that flash drive working. – Derek Jan 12 '13 at 4:19
If your video card has multiple power connectors, those aren't optional. Probably there was a lack of power, causing your issues. – Bigbio2002 Jan 12 '13 at 21:37

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