Excuse me, has your mobile phone been ROOT? According to your description, you can also enter: * # * # 00 1 # * * through the dial-up interface to view the NV parameters, where is_ROOT=0, indicating that there is no root, and is_root= 1, indicating that the root has been passed.

If ROOT says, you can try to restore the system with firmware upgrade. The way is to go to official website to download the firmware upgrade package to restore the system. Address of firmware upgrade for each model:/service.html. Enter this link, click "Service"-search for your mobile phone model in the search box, then select the model, click Resource Download-firmware upgrade, and download the rom package. This is a tutorial, you can have a look. Firmware upgrade description:/thread-1024055-1-1.html (please remember to back up your important information before upgrading). If it still doesn't work, you can go to the after-sales service center for testing and handling. The address and telephone number of the after-sales service center can be found in the Settings-More Settings-After-sales service menu. You can also check the address of the after-sales service center in vivo official website:/service/map.html.

If you have any questions, please feel free to consult us. Thank you very much for your support of our vivo. I wish you a happy life!