Need diagnosis help

[Brad67]

Hey,
I'm looking for some help trying to figure out exactly what is wrong with my PC.
About a week and a half ago my PC (which I've had for about 3 years and built myself) started to cut off power to 'most' of the internal components any time I would just start up any game (and a few times just booting up windows). I would lose power to the video card (and therefore monitor), mouse, keyboard, and from what I could tell the HDD too. But the weird part is that all the case fans and CPU fan stay on. I assumed it was the PSU since I've had PSU problems in the past and this issue was similar.
But then I used this as a justification to build almost an entirely new PC, replacing every part except the graphics card and HDD. Specs are as follows:
Operating System: Windows 7 Ultimate 64-bit
Motherboard: ASUS P8Z77-V
Processor: Intel(R) Core(TM) i5-3450 CPU @ 3.10GHz (4 CPUs), ~3.1GHz
Memory: 16GB (4x4GB) DDR3 RAM
PSU: 625W (up from 600 in my last PC)
Video Card: EVGA GeForce GTX 570
HDD: 1TB Western Digital (formatted when installed into new PC)

After spending all day building the new pc, updating windows and all the drivers, I tried out a game. I got in played for 5 minutes then it happened all over again. I have no idea why it's doing this. I've replaced everything except the graphics card and HDD.
Is my card drawing too much power all of a sudden? Or is my HDD corrupted and causing some shinannigans? I even thought of replacing the power bar that everything is plugged into but quickly ruled that out when everything else would stay on.
Any help would be greatly appreciated.
Thanks in advance.

 

[Brad67]

After talking to a few people it seems it's most likely the graphics card. I can use my RMA to replace it unless any one has any tips on a way i can fix it myself?

 

[clutchc]

What make/model 650W PSU are you using?

 

[Brad67]

It's a cool master RS-625-PCAR extreme2 power plus 625W psu.

 

[clutchc]

While not the best, that PSU should be sufficient for your system.
If the fans are connected directly to the PSU and they keep running while the +12V devices on the board fail, it sure would seem like a motherboard issue to me. Is that one of the items you have already replaced?

 

[Brad67]

Yep the motherboard is brand new. Only the gfx card and hdd are from my old pc.

 

[clutchc]

So, just to clarify...
The exact same issue that occurred with all the original components is continuing with all replacement components installed?

PSU: replaced
Board: replaced
Memory: replaced
CPU/cooler: replaced
Gfx card: original
HDD: original
Optical Drive: ?
Case: original

To be honest, unless you received a 2nd motherboard that was defective in the exact same manner as the first, the gfx card would be the next most likely prospect. It's rare, but I have heard of faulty cards corrupting the chipset/controller and crashing the system. I imagine the same could be said for the HDD too. But I haven't come across that yet.

Considering what you've spent so far in troubleshooting, replacing the card seems acceptable. Do you have access to another card of any type to use for awhile to see if the issue re-emerges? Or perhaps invest in a cheapie to see if it solves the issue?

 

[Brad67]

You're correct except the case is new too and so is the optical drive (my old optical drive never worked lol). I think i have my old 8800 gts lying around somewhere I could probably try. If not, my roommate is upgrading his ati 6950 (or something like that) so i can use his too. Ill check it out. Thanks for your help! I appreciate it. I really hope if i get the card replaced that it will fix the problem... :s