Hard grid, press and hold the volume increase key and the power-on key for several seconds at the same time in the power-off state, display the robot logo (I don't know what logo has a picture below) and then enter the recovery interface. A few lines of English will appear. Generally, select "Erase Data/Factory Rest" in the third line (the volume button moves up and down, and the power button confirms. After selecting "Erase Data/Factory Rest", it will appear again: No Yes-Delete ALLUERSDATA Select "Yes-Delete ALLUERSDATA" and press the power button to wait for reset. The first boot may have