graphicscard turns off?????????

[Tener]

Hey. I got new graphic card. Nvidia geforce gt 710 and it needs atleast 300w psu with 12v current rating of 20a, but my psu is 400w and it gives 12v current rating of 14a and here is my problem: My computer crashes when i play some games, sometimes even if im in internet. And then my monitor turns black and i have to restart my computer and if my computer reboots it shows me this error "application has been blocked from accessing graphics hardware". So why it does that? Really because of the psu? or maybe something else? My pc specs. Mobo: ECS GF7050VT-M5 (CPU 1)
CPU: Intel Pentium E5200 @ 2.50GHz
Wolfdale 45nm Technology
RAM: 4gb ddr2
Graphic card: Nvidia geforce gt 710 ddr3 2GB

 

[Doseq]

Install graphic card drivers http/www.geforce.com/drivers

 

[Tener]

I already have installed all drivers. And right now i have to use my old graphics card which is nvidia geforce 9500 gt and it does not go black. So maybe it is my psu problem?

 

[Doseq]

Well in case of PSU problem your computer should restart.
But you can give it a try and run OCCT PSU stress test - if during that test your pc will crash/restart/ screen go black then its most likely beacuse of psu failure.