"black screen/ recovery system/ reboot system now/ not working"に関する回答Try hitting the reset button on the back of your tablet. If that doesn't work then start the steps of a hard reset by holding the volume up button and the power button in while turning it on. Hold them in until you see the tablet logo appear. After that follow the prompts using your volume and power buttons. (Touch screen is not available at this point) try doing a factory reset. If this doesn't work then I suggest returning it to the seller.