I had a similar problem with my new setup which was based on the KT7A-
RAID. When I got everything assembled and was ready to go, I hit the power 
button and the system started and then shut itself off after about 2 seconds. 
This happened several times before I took everything apart and and put it all 
back together again. The result was the same the second time around.

Check pages G-1 and 2-12 of your manual. Try clearing the CMOS as 
described in the first question of the troubleshooting section. This is what did 
the trick for me.

Not sure if this will help since your system is totally unresponsive. Mine at 
least started the fans spinning before it shut itself down.

Mike