new build keeps randomly shutting down

[Destry300]

I finally finished my first PC build and everything is working fine besides the fact that my computer randomly shuts down without warning. I never have anything crash to the desktop, just an instant shut down. For a little while I was getting a +3.3v voltage warning from the Asus AI Suite 2 but I read that the program is complete crap and to disregard any messages from it. I also uninstalled it to see if that was the problem but to no avail. I've been using Speccy to monitor temps and everything seems to be in the correct range. What could be causing this?

my build: running on windows 7
Rosewill Thor V2 Tower
Asus Sabertooth 990fx R2.0
Amd fx-6300 cpu
XFX XTR 650w power supply
G.Skill Ripjaws X series 8gb (2x4 gb)
LG black blu-ray drive
Seagate Constellation 1tb 7200 rpm 128 mb hard-drive
Samsung 840 pro series 128gb solid-state drive
Asus GTX 660 2gb 192-bit graphics card

 

[Ninjaxsl]

I finally finished my first PC build and everything is working fine besides the fact that my computer randomly shuts down without warning. I never have anything crash to the desktop, just an instant shut down. For a little while I was getting a +3.3v voltage warning from the Asus AI Suite 2 but I read that the program is complete crap and to disregard any messages from it. I also uninstalled it to see if that was the problem but to no avail. I've been using Speccy to monitor temps and everything seems to be in the correct range. What could be causing this?

my build: running on windows 7
Rosewill Thor V2 Tower
Asus Sabertooth 990fx R2.0
Amd fx-6300 cpu
XFX XTR 650w power supply
G.Skill Ripjaws X series 8gb (2x4 gb)
LG black blu-ray drive
Seagate Constellation 1tb 7200 rpm 128 mb hard-drive
Samsung 840 pro series 128gb solid-state drive
Asus GTX 660 2gb 192-bit graphics card

My friend you might have an issue with either a component in your first build which is causing and forcing your system to instantly shut down, or you need a new power supply because I don't trust XFX as much as i trust a Corsair Bronze + Edition.