Its not getting power or its not working? Are you running it iff a dedicated powered Hub?
This has cropped up a few times with me but the componants have worked fine. I'd do a cold shut, reconnect to another hub, and then start her up again. Power thru the USB ports can be a very touchy thing. My problem is the opposite. I cant power them down, even when the puter is off. The only way would be to disconnect power to the dedicated Hub, and Im never doing a thing again to a working system.
Im done tinkering with working systems.