I've just put my first build together and tried plugging it in for the first time.
The blue light on the front of the case came on and the CPU cooler turned on, for about 5 seconds and then they turned off. After a few seconds it did the same again, and then again about 6 times, but then it stayed on, but nothing is showing on the monitor.
First I tried plugging the monitor into the graphics card, and then right into the motherboard on-board video, and still nothing on the screen.
I then turned the computer off, and on again. This time it only did the '5 seconds on, and then turn off' thing once and then stayed on, but still nothing on the screen.
the first issue it could be is the mb that it an x68 and your using a ib cpu is the mb bios has not been flashed yet to use the new cpu. see if there a bios sticker on the mb. most time it at the end of the serial number sticker. check to see if the bios is up to date. if not see if someone has an older sandy cpu that you can boot and flash the mb or see if a local shop can help you there.
if not you have to send the mb to asus and ask them to flash it for you or replace it with a mb with the newest bios or a z77 mb. the other issue could be ram and mb not liking each other. have you tried one dimm and walked it?? also try removing the gpu and see if the system will post with onboard video. also make sure that all the power 24 and 4/8 pin are connected.