That could still be caused by a lack of power to the board. Again, since you haven't provided much detail, I can only assume that you've checked basic things like tripped circuits, bad PSUs, etc.

If you're really desperate to get it going, and don't mind voiding your warranty, you can open it up and connect directly to the two boards with a PC. I've never done this, so proceed at your own risk. I'd only recommend this if you have quite a bit of time on your hands.