It may be the problem of wifi driver

Solution : uninstall the wifi driver and reinstall it

The display is not changed into HDMI mode or the HD cable is defective

Solution : Change the HDMI or display

The driver is not compatible with the updation

Solution : install the driver or flash to the factory set

The important files in system may be lost

Solution : flash the factory set

The tablet connects keyboard and restart the tablet and choose "Yes" to click "enter"

The charger or the usb cable is defective . The battery level is low or the battery is protected

Solution : please get the tablet charged for an hour and press the power button for seconds

The system may crash or important files are deleted

Solution : flash the image

It may be the compatibility problem of the TF

Solution : Please take out the TF card and put it in again

It may be that you reset the tablet or the antivirus software deletes the drivers. It is recommended please do not install antivirus sorfware.

Solution : Install the drivers again