Around Christmas of last year I built a PC that I've been using for gaming, after taking a few hours to assemble it all it worked flawlessly and I never had any problems with it. A few days ago I was playing a game and my computer just up and shut off without warning, afterwards it wouldn't turn back on. I tried to barebone it and got nothing, I tried taking it apart and putting it together again and got nothing, I tried booting it without RAM, and nothing, I tried booting it without the video card and got nothing, I also tried clearing the CMOS to no avail. I assumed that my PSU died so I ordered a new one, replace it and connected everything again and still, nothing. If I press the power button after letting it sit for a while, the power LED will flash on the inside of my case and the fan will turn for a less than a second and then I get the same nothingness as always. I'm completely out of ideas on what to try so the only thing I can think of that'd be causing this is a dead mobo, however I'd like to get some other opinions before shelling out a few hundred dollars on a new one. I'll post my specs as well if that'll help any. Thanks.
Case: Cooler Master HAF 912
Motherboard: ASRock Z77 Extreme4
Video Card: Sapphire Radeon HD 7950
RAM: 2x Kingston HyperX 4gb
CPU: Intel i5 3570k
PSU (Old/Original): Antec NeoECO 620w
PSU (New/Replacement): Rosewill Green Series 630w
Case: Cooler Master HAF 912
Motherboard: ASRock Z77 Extreme4
Video Card: Sapphire Radeon HD 7950
RAM: 2x Kingston HyperX 4gb
CPU: Intel i5 3570k
PSU (Old/Original): Antec NeoECO 620w
PSU (New/Replacement): Rosewill Green Series 630w