Users of the Apple iPhone, iPad, and iPod Touch are experiencing a common issue: no sound is being played when they watch a video. These are some possible causes.
How To Fix iOS Video Has No Sound
Make sure Volume/Ringer is turned up
Turn the volume/ringer all the way up. To get the song/video to play, some users had to open the Music or YouTube apps.
It is possible for the device to detect something in the microphone and not play sound through it. While recording, make sure your finger or case does not cover the microphone hole. If necessary, you can clean the microphone jack with compressed air or a toothpick.
Make sure to check the microphone and speaker for any foreign objects or lint. It seems that a needle works well for cleaning them.
Airplay is on
Make sure Airplay isn’t allowing a connection to another device. To access the Control Center, swipe up from the bottom to reveal it. Select the ” AirPlay” icon to disconnect any devices.
Charging Jack Clogged
Although I haven’t personally experienced it, some users reported that the charging jack can be cleaned.
One of these solutions might solve your problem. Please share your experiences in the comments section.