Apparently my chip died, working fine one day and dead the next. Done everything from deleting the device, rebooting, disabling fastboot, doing a reset of the PC, etc. Called MS, they said I'd done everything and I'd have to send it in, but my only option isn't for repair but rather to BUY A REPLACEMENT ONE at half price - $450. I'm sorry but that's crazy. A device 3 months out of warranty and there's no repair option of $100-200?