1. Try to restart the phone forcibly first to see if it can be used again.
Forced restart method:
① ① models of funtouch OS 3.2 and subsequent systems: press and hold the "power button"+"volume reduction button" 10 second at the same time;
② Press and hold the top round key 10 second or more to forcibly restart the mobile phone (NEX 3/NEX 3S is applicable);
③ Model of the system before ③Funtouch OS 3.2: Press and hold the "power button" for more than 12 seconds;
2. If it can be used again after operation, you can try the following methods to avoid the failure from happening again:
① Confirm whether incompatible applications are running.
Some third-party software is incompatible with the system, which may cause the phone to crash and restart. It is suggested that you can back up the software data first, and then set >; More settings/applications and permissions > application management > find the corresponding software > store, click "clear data" and "clear cache" to view it, and if necessary, uninstall the software and re-enter the application store to download and install it;
② Check the storage space of the mobile phone.
If the storage space is low, the system performance will drop sharply. It is suggested that I housekeeper should be used to clean up the storage space of mobile phones in time, uninstall uncommon software, and keep the remaining storage space above 20%.
③ System upgrade
Check whether the mobile phone system version is the latest version (some models are being set up-system upgrade) in the interface of mobile phone settings-my device -ikofun Touch OS/Monster/UI. If a new version of the push notification is detected, it is recommended to update to the latest version in time. System update will improve the compatibility and stability of the system for third-party applications, and some new versions will add some new functions.
4 reset the phone.
If necessary, you can back up your phone data, and then go to Settings > System Management/More Settings > Backup and Reset > Clear all data to reset your phone. This operation will delete all data, including: software, SMS, contacts, memos, etc. Please back up important data before operation to avoid loss.
3. If the above methods can't be solved, please back up the mobile phone data in advance, and take the mobile phone and purchase certificate to vivo customer service center for testing. The address and contact information of the service center can be found in vivo official website-Services-Outlets-Select your province and city-Inquire about the local customer service center, or enter this link to inquire.