PC randomly shuts off and turns back on no post

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1

Okay so first off, I've noticed it for a while now, last time I had this issue the GPU was faulty and got RMA'd, but the issue is happening now, except last time it wouldn't post at all ever... Now it posts if I restart it. basically the computer shuts down instantly, almost as if the power was cut, then it turns back on and refuses to post until I hard shut down and turn it back on. Am i running into a power issue? or?

The parts I have are:

ASUS GTX760-DC2OC-2GD5 GeForce GTX 760 2GB 256-Bit GDDR5 PCI Express 3.0 x16

http://www.newegg.com/Product/Product.aspx?Item=N82E16814121775

 

ASRock Z77 Extreme3 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157330

 

CORSAIR CXM series CX600M 600W ATX12V v2.3 SLI 

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139050

 

Intel Core i5-3350P Ivy Bridge 3.1GHz (3.3GHz Turbo) LGA 1155 69W Quad-Core Desktop Processor 

http://www.newegg.com/Product/Product.aspx?Item=N82E16819116782

 

G.SKILL Ares Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory 

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231544

 

I also have a 1TB hard drive that I picked up.

 

Thank you for your consideration and help.

2

check the voltage on your psu 24 pin. are you using a power conditioner/ups? It may be a bad chip or mobo but start with the psu first. Also double check your case and motherboard grounds and your wall power.

3

... unseat and reseat your graphics card and RAM. Usually it will beep at you if they're not in all the way but not always. 9/10 this is the problem with bootcycles like this or if it's just running the fans and not posting.