Why is there no sound on Apple's mobile phone?

There is no sound on Apple's mobile phone for the following reasons:

1, mobile phone setting problem: the mobile phone is set with no beep or the notification option is turned off. Enter Settings to set the information reminder of the mobile phone.

2. The ringtone is set to none: the ringtone of SMS is set to none, and you can go to Settings-Sound-SMS ringtone-and select a ringtone as SMS ringtone.

3. The phone has turned on silent mode: when the phone has turned on silent mode, there will be no sound when receiving information. You can turn the mute mode on or off by dialing the mute button on the side frame of the phone.