About a 5 weeks ago I built my new system. Had 2 issues with the mb. Just received my new mb from a different manufacturer. Today I put it all together and it doesn't power up. I got the Asus P8Z68 V Pro. Memory is compatible. I just spent $50 get the system diagnosed so I know the PS works. The MB lights up but when I hit the power button....nothing. I hit the Memok button and it flashes red once and goes off. Everything in the comp is new. I have a lot of $$$ invested and I still don't have an operating system. Does anybody have any idea what it could be?
Try breadboarding the sytsem by placing the board w/CPU/HSF/1 stick RAM on an insulated surface and connect just the PSU cables (24 and 4/8 pin), monitor, and graphics card if no on-board is available. Using a screwdriver or other metalic object, short the 2 pins that the front panel power switch would plug into. See if you can boot into BIOS.
(BTW, When you remove the board, check to see if you inserted one too many standoffs. Grounding out the back of the board could cause a no-boot situation.)
This is actually a common issue with Z68 boards in general. I have the same issue with that same motherboard. Where it turns on then off 3 times then starts. Its a problem with boot cycling although upgrading to the latest bios seems to fix most of the issues i was having. Hope this helps.
Like clutchc said, take a look if you have too many standoffs. Every hole in the motherboard is not necessarily compatible with every hole in the case. A standoff on the case that touches the back of the motherboard without a hole for it can easily short circuit the board. I had this same issue over a year ago -- try this first.
Thanks for all the replies. I did what you told me. Here I had the 8 pin power cord in backwards. Don't ask me how.... It was working fine. I was updating things. Left my computer on while I did some errands. Came back and the comuter kept restarting ove and over again. It restarts every sec. So now I am just about right where I started....It doesn't even reach the bios. Just don't know what to do. I'm ready to send everything back and be done with it...