Just an update, my motherboard like totally dead, z68xp-ud3, i disconnect the power cable from psu to mobo, then replug, when psu switch is ON, see a green light come out on GPU for an instant, then thats it.
Another owner of mobo same problem, what he did was to remove battery, and let mobo rest for 2 hours, then put it back on and boot. Hope it works later.