Unplug EVERYTHING on the mobo... USB connectors, CPU, RAM, video cards, sound cards, etc etc... Let it sit for 1-2mins and then ONLY plug the power back in and try to boot and listen for the beeps.
If you start getting beeps add the CPU back, then check for beeps again. If its still beeping add the RAM, check again and if its still beeping, add the video card. Also, if you have an led read out on the board check that and what its telling you at each step.
If you dont get any beeps or anything from the mobo after you had everything unplugged, then reset the CMOS and try the steps above.
The reason Im telling you to unplug everything is because in the past I have had several things before that were being grounded out or that were faulty and were interfering with the mobo after being moved around.