So, my computer likes to shut off when I'm playing games. I've narrowed it down to a few select moments that I use to test my things. At the end of the Call of Duty MW2 campaign, where you chase the general through the desert and the sandstorm rolls in, it shuts off. The thing in question is here in http://www.youtube.com/watch?v=rZnD0aoEaJs at 1:52. I'm pretty sure it has something to do with smoke and particle effects, but regardless, it's very annoying. My system specs are:
Intel(R) Core(TM) i7 CPU 860 @ 2.80GHz (8 CPUs), ~2.8GHz
4 gigs DDR3
NVIDIA GeForce GTX 260 Superclocked edition
Sure does sound like power supply faliure I have heard nothing but bad things about Coolmax PSU's. The scene you are talking about is very GPU and CPU intensive so if there is an insufficient amount of power exactly what you describe would happen. To make sure though download OCCT it has a power supply torture test which will load up your cpu and gpu to max if it shuts down there its 1 of two things heat or lack of power so also keep an eye on your temps.
If you do end up getting a new PSU I recommend Antec been using them for over 10 years and never had a problem with them.
Yes, it reboots after shutting off. So I ran that OCCT test, and my computer shut off rapidly. The temps were perfect, but after about a minute, it rebooted. So now, I need a reliable PSU, for a pretty good price. But I'm willing to shell out some cash on this because it's a vital part of the computer.