Have you already tried by using a fresh new install of the image in your SD card just to double check? Download the image again, extract it into your SD card and try again to see if the USB work. Also remember to try to update the board without the SD card. And finally are you by any chance using an USB stick 3.0 for the recovery? If this is the case I’d suggest you to use an USB 2.0.
Regards,
JPMontero_Intel