Hi, I've recently put together a new system as shown below:

Asus P5N-D SLi Motherboard
Core2Duo E7300 2666mhz with Arctic Cooling Freezer 7 Pro Fan
2 x 1Gb Corsair XMS2 DDR2 800mhz
Zotac Geforce 9800GT 512mb
550w ATX PSU
1 x 120Gb IDE HDD (Master)
1 x 240Gb SATA HDD

It generally runs quite well, however when I try to play a game (TF2, NS or EVE) it runs for about 5-10mins before my computer just shuts off in an instant. I'm fairly sure its not my cpu or gfx card overheating as I currently have them both underclocked in an attempt to fix the problem, this has merely extended the time before it shutdown by an hour or so sometimes but most of the time it still cuts off after 10mins.

Here's what a speedfan of my comp idling looks like, i'll get one in a min of my comp while EVE is running:

GPU: 45C Temp1: 49C Temp2: 48C Temp3: 22C HD0: 53C HD1: 47C Temp1: 40C Core 0: 45C Core 1: 45C

Vcore1: 0.96V Vcore2: 3.22V +3.3V: 0.00V +5V: 5.03V +12V: 12.03V -12V: -16.97V -5V: -5.41V +5V: 4.97V Vbat: 3.23V

Any suggestions of what might be causing it to just turn off would be great :)

Oh thought i'd just add that temperatures are generally high because its like a sauna in the attic today, and after running EVE for a bit with speedfan open so i could see my temperatures I'm fairly certain its not overheating as both cpu and gpu aren't going above 50C. Could this mean that its my PSU running out of juice everynow and then or ??

just a thought if you haven't all ready checked, re-check the chip and if seating is ok and thermal paste is ok.

Yeh my fan is securely seated ontop of my cpu, and by the cpu temp never really going over 45C i'm assuming the paste is alright.

i noticed in BIOS that my Vcore Voltage of 0.94V was highlighted red, so i've put this back to 1.2V to see if it makes it more stable, but i'm gonna leave my gfx card underclocked for now.

ok hope you solve it, i had oveheating when burning dvds and ended up being fan cooling pipes (laptop) had a small clump of lint blocking one of them, so simple but hard to find.
keep searching youll get there.
sorry can't help more,
good luck.

After a bit of reading i've discovered Temp1 is the MB temperature, and thats the highest one going upto 55C when I play games which can't be a good thing, so i'm gonna try installing the optional chipset fan that came with my motherboard and see if that makes any difference. However the chipset fan say only use it if you aren't using active cpu cooling, i'm guessing this means a cpu fan, but i reckon that arctic cooling fan is beefy enough to take a slight airflow reduction.

I'll post how it goes.

[edit]Hmmmmm Mb Temp still hitting 50C but will see if its low enough

It sounds like a faulty PSU problem to me... Sounds like once your computer starts up a game & the CPU recieves more voltage along with the GPU & other components recieving more (for example the GPU will change from 2D mode to 3D mode & start consuming more power, which is also why components get hotter at these times aswell obviously) once that happens it seems like the PSU is just shorting out or a component isn't getting enough juice, it depends on how your comp handles it, in my experience my comp handles not enough juice with a BSOD other than pure shut down. (Experienced when overclocking) but yea I'd suggest you try an alternative power supply just to see if that alleviates the problem.

Sadly I don't have another PSU around to be able to test it, however I get the feeling your right, its just not quite enough to run everything.

Any recommendations on a PSU that'd be able to run that lot plus maybe an extra GFX card? As the MB has SLi

Well it's not that the PSU itself isn't likely enough although it might not be, it depends the most important part of the PSU is actually the amps it puts through the rails, if that isn't enough (especially for GPU) then you will end up with problems. However sometimes PSUs just starts to malfunction.

As for PSUs well Corsair make good PSU although they are often kind of pricy. OCZ or Arctic Power are also pretty good. (I have an Arctic Power PSU, which runs my comp consisting of a Q6600 overclocked to 3.2GHz, HD4870 (which is power hungry) & 4 SATA II HDDs, along with 4GB of RAM, to which it is on 24/7) My general advice on PSU is don't go the cheap route, because the PSU can take other components with it & a cheap PSU can result in the need of a whole new computer if things go wrong.

I would have thought 550 corsair would have been up to it. It is a little less than you would want running two hdd + after market cpu cooler and a dvd drive. 650-700wts would be better.

Have you actually observed the fan on the gpu running with the case side off? I have had this problem with a couple of cards and the fan starts up all right and registers with fan speed programs but it can fail at any moment. It only takes a couple of mins for the temp to skyrocket and the system will shut down.

I have always taken the poxy factory fans off my cards and cable tied on a case fan pluged straight into the psu, this way the fans always going independant of the card and it pushes alot more air over the heatsync.