Oppo R9s suddenly has a message reminder, but I can't find what it is. What should I do?

Go to phone settings-sound and vibration-information ringtone to set it. Sometimes it is an incompatible third-party software or a reminder of file damage or loss in the mobile phone system, so shutting down and restarting can generally solve this problem.

There is no solution to the sound problem when the information comes from the mobile phone;

1. Find the settings of OPPO mobile phone, and then select the sound and vibration options to see if mute mode is turned on;

2. If there is still no sound reminder after turning on mute, check whether the default setting is do not disturb mode;

3. You can also enter "Settings"-"Sound and Vibration" to check whether the option of information notification is displayed as off, and if so, turn it on;

If there is still no response, take it to the shop for repair.