New-built system trouble, and I need your help.

Hello everyone, I am a new member here. I just built a new computer system by myself. This is my first time to build a system too.  
This is the components of my system:
1. PSU OCZ Modxstream pro 700 W.
2. HDD western digital caviar blue 500 GB SATA 6.0Gb/s.
3. Case cooler master HAF 912.
4. ASUS 24x DVD Burner.
5. Motherboard Asrock 990FX Extreme3.
6. CORSAIR Vengeance 16 GB, DDR3 1600.
7. Graphic card: GTX 480.
8. AMD chipset: AMD 4100 fx.

I installed all the components successfully. I checked all of the cables. However, when I plugged in the psu, my motherboard does not work. I do not see any lights on it. I did check the pin of power switch and the reset. I tried to reverse the pins, but it still does not work.

I tried to connect a case fan directly to the psu, and the fan does not work neither. I am thinking about return the psu and get the PC Power and Cooling Silencer Mk II 750W. Because it has long cables. So, it is easier for me to manage the cable, and that is a good psu too.

So, what are your opinions about the trouble I am facing now?

I am looking forward to receive your replies.

Thank you in advance, and have a nice day.