Power Problem ASUS MAXIMUS FORMULA V

Just bought all new hardware for a gaming PC, The problem is when i switch my power supply on, the computer starts up and runs for about 3 seconds then shuts off. also if i reset the cmos in the back the computer will do the same thing again. note this is without me even pressing the power button the case. After the power off the start and reset button are still lit up and the red led's on the motherboard are still lit. I have also tried unplugging all hardware to the mobo just to see if it will boot up, not matter what hardware is connected it will still do the same thing.

MOBO: asus maximus v formula
CPU: I7-3770K
PSU: corsair hx750
RAM: g-skill ripjaws


Video below.
Problem with custom. - YouTube

That particular board has the main 24-pin ATX connection on the right hand side of the board, and an 8-pin AND a 4-pin connection at the top left/middle of the board. Are all of these connections seated fully? Some say you only have to plug in the 8-pin at the top, but you might need the 8-pin and 4-pin as well.

I built a computer last month using the same mobo, and I was having the same problem. Kbrady is correct you need to plug both connectors.

Awesome ill try plugging in the 4 pin as well tonight and will update with the outcome.