First things first, make sure the switch on your psu is on and the psu is plugged into the wall (done both of those before). second, are you getting a light on the MB when it is plugged in? If there's no light, the board isn't getting power, or it's fried. If you get a light, but still nothing else, sounds like there's a possibility of your case power switch being plugged in the wrong place or backwards or something (done that before), or maybe the switch is broken. beyond that, i have no idea.