Why is there no sound in oppo r9s SMS?

Processing method of mobile phone receiving silent information;

1. Check whether mute mode is turned on: setting-sound-mute mode-turn on full mute function;

2. Check whether the phone has turned on the Do Not Disturb mode: Set-Do Not Disturb mode;

3. Has the mobile phone turned off the switch of the notification center: Settings-Notification Center-Information-Allow notification, status bar display, and screen lock display (at present, only ColorOS 2. 1 system has this function);

4. Whether to turn off information notification in mobile phone information settings: information-settings-information notification;

5. Check whether the contacts on the mobile phone are open. No reminder in this session: contact person-contact information-no reminder in this session.