Please press and hold the power button 10 seconds or more to force a restart. If it still doesn't work, it is recommended that the mobile phone be double-cleared, which will lose data. When the machine is turned off, press the power button+volume increase button at the same time to enter the recovery mode and clear all data. Select Erase Data/Restore Factory Settings, and click Yes after the interface jumps. When finished, return to the original interface and press Restart System-restart the phone immediately. The first boot may be a little slow, please wait patiently. If not, it is recommended to go to the after-sales service center. The address and telephone number of the after-sales service center can be inquired at the homepage-service-outlet of vivo official website.