Computer won't start the power.

Okay, I'm currently building a new computer.
Asus mother board with Antec 480 Blue LED power supply unit.
We got the computer built and connected the power cord to the mother board and turned it on. The LEDs in the power supply blinks and shuts off. Standby power light is "on" on the mother board but the hard drive doesn't start up. Neither does the Zalman Heatsink power up.

We tried to put the power on another computer, power blinked once again. Computer did not start. We got another power supply unit and tried it on my mother board. Fan spun for a sec and then turned off. Tried it on the other computer and it worked.
I have no idea what's going on and frustrated from connecting all these stuff to my computer. So many wires!!!! ahhhh!!!!

Help me please~~!

Make sure your motherboard is properly mounted and isn't shorting itself out on the case.

most mobo's have 2 places where you connect the power cables to the mobo. Make sure you did both.

It's also possible that you don't have the power leads connected properly, because there's a different lead for pwr led and pwr sw.

I had the same problem. My motherboard showed a power light, but nothing worked. Get a local shop to run a diagnostic on the computer. It will cost $35-50 and they will able to tell you what is exactly failing. In my case it was the motherboard.