If the audio is intermittent when playing the video, please follow the below methods to do the troubleshooting:
1. Make sure that there is one video input source inserted in the TV.
2. Unplug all other electric appliances from the wall socket except the TV.
3. Change another video to play on the TV.
4. Change another cable to connect the device to the TV. If you plug the device into the TV via the HDMI cable, please change another HDMI cable if you have a spare one.
5. Try to restore the TV back to the factory settings: press the Home button on the TV remote. Then select Settings Device Preferences Factory Reset.
6. If the TV has internet access, please check if there is a new version of software updated online or not.
Press the Home button on the TV remote, and select Settings Device Preferences About System update Network Update:
If the issue cannot be resolved, please feel free to call the TCL hotline for further help.