[ Desktops ] Open Question : New computer wont boot.?

[ Desktops ] Open Question : New computer wont boot.? References Alright, round 2. I\'ll be a little more specific. A friend of mine built a gaming rig. Mobo: MSI Big Bang-XPower II PSU: 850w corsair CPU: i7 ivy bridge GPU: GeForce 780 HDD: 1Tb SSD: 512Gb We get everything put in and plugged up, and it wont boot to bios to start installation. It just turns on and off every 15-30 seconds. All the fans kick on, the LEDs light up, everything starts. Except it wont boot. I dont know if this is a power supply, HDD/SSD, issue or what... Ive wracked my head for days trying to figure it out. We have rewired everything, reset all the hardware (gpu/ram/etc), and made sure everything was wired up correctly. But still, the exact issue, it wont boot to anything. Just power cycles every 15-30 seconds, we are going to test the PSU tomorrow but outside of that, I dont know what would cause it not to boot after double checking our wires and hardware. He\'s dang near 3k into this thing (after shipping and such) and we can\'t get it booted. VERY irritating, my mini-itx build went smooth as silk. I just feel terrible and helpless, because Ive never encountered this problem.