Computer was randomly shutting down while gaming, was it the PSU

[indigo0086]

I recently built a new pc with the following components:
ASUS P8Z68-V PRO LGA 1155 Intel Z68
Western Digital VelociRaptor WD6000HLHX 600GB
CORSAIR Professional Series HX750 (CMPSU-750HX) 750W ATX12V 2.3
G.SKILL Ripjaws X Series 16GB
Intel Core i5-2500K Sandy Bridge 3.3GHz (not overclocked)
HIS Radeon HD 6950 IceQ X Turbo 2GB (256bit) GDDR5

After putting it together it worked fine, adequate cooling (have an Antec 300 gaming case with 4 fans, good cpu cooler, at a low of 35, high of about 48-50. I noticed that when playing certain games my computer would just shut off randomly, then after a while the computer would recover and boot up. I thought it was at first the cpu so whenever I played a game I'd keep realtemp on and the tempurature was nowhere near TJ Max. So I thought it was the power supply. I RMA'd it to the manufacturer and they are returning it to me. In the mean time I temporarily bought a power supply so that I can at least find out if it was indeed that component and no other.

My question is how do I really reproduce the conditions before the shutdowns other than playing games. Are there diagnostic tools that monitor each of my components to see any anomolies. I tried the asus pc diagnostic tool and it of course passes, but I've done a cpu load test (IntelBurnTextV2) and that was fine, so I don't know how to approach finding the issue.

 

[americanbrian]

An issue I have seen several times is the graphics memory overheating. only the GPU temp is ever monitored by utilities (there is no sensor for the RAM).

I have a card that I managed to stop crashing by turning the GPU fan speed to 100%, which passes more air and cools the ram chips more effectively. It is annoying as it is significantly louder, but I am expecting a new card soon so it keeps me playing for now...

 

[indigo0086]

Hmm, The graphics card I have is pretty well cooled, it has a heat-pipe system and the fans I believe cool quite well. I haven't run a diagnostic but I'll look into it.

 

[americanbrian]

I have no doubt that the GPU is cooled very well, but are there thermal pads to move heat into the heatsink block? are they all seated properly? if they don't have pads (some designs simply don't) then what takes the heat away from them?

Only air passing from the GPU fan or case cooling.

 

[indigo0086]

Either way, I would like to know of a sure way to determine that the problem is a certain component other than returning it and hoping for the best.

 

[indigo0086]

By Sure I mean Empirically sure.

 

[americanbrian]

Ok, well, it is a process of elimination.

I simply used ATI overdrive to to set the fan speed to %100.

Try and duplicate the problem with those specific games (worst offenders first). If you find it impossible to duplicate the problem after a day or two then it is likely that it is your problem.

To be doubly sure then simply restore the previous fan settings (restore factory settings in overdrive) and if the problem is then reproducible then you can be very sure that this is the problem.