My computer is shutting down by itself and doesn't want to restart

[Oscanto]

Hello,
First of all, i'm French so... Sorry for my English.
I recently build a computer for the first time, here are the specs :
Motherboard : M5A97 Pro
CPU : AMD Phenom II X4 955 BE
GPU : MSI R6870 Hawk
Ventirad : Cooler Master Hyper 212 Plus
PSU : Antec HCG 520
Ram : Kit dual channel DDR3 Ripjaws X, 2 x 2Go, PC3-12800, CAS 9, G.Skill
DVD writer : LG GH22NS50
Hard drive : Caviar Blue 500Go
Wireless card : TP-LINK TL-WN951N
All in a Zalman Z9 Plus

The problem is that when I play Crysis, my computer is shutting down after 30 minutes, and doesn't want to restart... I have to unplug the computer and wait 1 or 2 minutes...

Temperatures seem to be good, CPU : 30°C GPU : 38°C and 40°C/46°C playing Burnout Paradise
But my bios says my CPU temp is 44°C

I also tried to launch FurMark test, and 2 sec after the beginning, the computers crashes...
After that, I tried OCCT, CPU stress test seems to be ok, gpu stress test makes the computer crash after 2 or 3 minutes, and PSU stress test makes the computer crash just after the beginning, before the screen appears...

Is my PSU defective ?

It's the first time I build a computer, therefore maybe I have made some mistakes...

Thank you for your help

 

[Ubrales]

Antec is a reputable brand like Corsair and Seasonic, but 520 watts may be on the low side. Since the temps look good, I would suspect the PSU.

Is there a higher wattage PSU (650 watts to 750 watts) that you can try to install and check performance?

 

[Oscanto]

No, I can't try with another one... :/

 

[Ubrales]

"... and PSU stress test makes the computer crash just after the beginning, before the screen appears... "

From this, it is the PSU.

When you replace the PSU select Corsair, Antec, or Seasonic and go with 650 to 750 watts.

 

[Oscanto]

Ok, thank you for your help
Do you think this one is enough ?
http://www.antec.com/Believe_it/product.php?id=MjU2MA==

 

[cmichael138]

http://www.antec.com/Believe_it/product.php?id=MjU1OQ==

 

[Ubrales]

Ok, thank you for your help
Do you think this one is enough ?
http://www.antec.com/Believe_it/product.php?id=MjU2MA==

Yes Antec is a reputable brand! It will work fine. Just pick one with a good wattage, 650 to 750 (higher if prices are fine).

 

[Oscanto]

Thank you very much for your answer, i'll take a higher wattage ( maybe the one that cmichael138 shows me ) ...
I really thought that 520W was enough...