Sorry to hear about this. How about:
- can guvcview work with some other usb camera on your computer?
- after you plug in jevois, type dmesg in a terminal and look for error messages there, see http://jevois.org/doc/UserConnect.html
towards bottom of page
- sometimes if the camera is detected but guvcview hangs, this means bad usb cable or weak usb port. Basically, power is ok during boot, but not enough when machine vision starts.