I'm Super User ROOT, ROOT BROWSER program by entering the file "VOLD.FSTAB" which is used to detect the SDCARD delete that file because several attempts failing stay, when you turn the tablet does not boot it stays on the android logo. reading I realized that the modified SYSTEM folder files are not regenerated by the FACTORY RESET .. it only starts when you have the usb cable connected, sorry if I do not understand well I do not speak much English