A little help please!

[exxr1c]

The story goes like this. I recently built a computer and everything was working fine the first few weeks, then out of nowhere my computer starts experiencing power up problems. I woke up one morning to turn it off and it booted up for a few seconds then cut off. I try a few more times and the exact same thing happens. Hastily assuming it was the power surprise I went and purchased a Antec 400W High Current Gamer. Installed and the same problem occurs. Next, I started to trial and error. I have backed off the standoffs,rearranged the ram, reconnected everything, changed outlets, changed power supplies as previously mentioned, reseated my CPU and heatsink/fan, flashed my BIOS, reseated my video card and a few other things. It will boot every now once in a while, but I can't seem to place the blame on anything. Looking for some outside input and help. Thank you in advance. ANY input is greatly appreciated.

Here are the spec's:
ASrock 760GM-GS3 Motherboard
AMD Phenom X4 965
Antec 400W High Current Gamer PSU
2 2x2GB G.Skill Ripjaw X Series 240 pin DDR3 1333
MSI Radeon 4350 64 bit DDR3 PCI 2.0

[itsakjt]

Problem seems to be with the motherboard. Since you have tried a new power supply, the only startup circuit that remains is the motherboard. Get the motherboard inspected or try a different board.