Yes formated Fat32. Will not update from usb. Tried recovery and that does not work either. Need to get back to stock or root.

Tried to return to stock keep getting usb data error. Now box is not root but can not update or return root either. I have used many different usb drive and always get usb data error. Someone please help. I want to return to stock, if that is not possible then how do I get back to root?