Screen blacking out / system halting - GPU or PSU problem?


Sep 14, 2011
Hi all - to start with, here's my rig

AMD Phenom X4 955
Gigabyte GA-MA790XT-UD4P
4GB DDR3 GSkill RAM (2x2gb)
nVidia GeForce GTX275 (896mb)
Corsair 850w PSU (don't have the model number handy at the moment)
Windows 7 Home x64

These parts were purchased in June 2009, and have had zero problems until now.

I'm currently having an issue in which my screen blacks out and the system hangs. It's not a full shutdown, so the PC is still on after it blacks out and needs to be rebooted. This generally occurs either when trying to watch a video or play a game - however, it's very inconsistant. I can play an intensive game for a long time with zero problems (games like TF2, StarCraft 2, etc.). I can also watch videos for a long time with zero problems.

However, once every couple of days or so, I have the problem I described above, and it usually occurs within a few minutes of launching a game or movie. If I reboot, the screen may black out again after reaching the desktop, even before I can relaunch my video/game. After a couple reboots, the problem typically goes away. This originally led me to believe it might be temperature problems, but after some close monitoring, that shouldn't be the case. GPU runs at 48-50 while idle, upper 60s during load. CPU temps are very well in the safe range - I have a pretty monster heatsink in my rig, and even under load the CPU temp doesn't even get close to anything problematic.

So I'm led to believe my PSU might be crapping out, and when it acts up, the GPU is the first thing that loses power, thus hanging up the system. Does anyone else think this might be the case, or is it something else? I'm pretty experienced with computers and hardware problems, but PSU issues have always been a gray area for me, so if anyone has any thoughts/ideas, I'd be very glad to hear them.


I think if your PSU was failing it would be rebooting your whole system entirely, not just flicking the monitor off.

Sounds like a failing GPU more than anything else or at the least a lose connection.

Do you have a different monitor you can test for a few days to rule out the possibility of yours being broken?


Jun 8, 2007

I have seen tdl4 boot block rootkits do things like this most av's do not pick them up you might want to download tdsskiller and scan your machine.

Other than that it could be a corrupt video driver, i would remove and re-install the newest driver and make sure directx is up to date.