If the TV has the buzzing/clicking/knocking/popping sound when playing video, please follow the below methods to do the troubleshooting:
1. Change another video to check if the TV could play it properly or not.
2. Change another cable to connect the device to the TV if you have a spare one.
3. Try to restore the TV to the factory default settings.
Press the Settings 
button on the TV remote, then select Settings --> System --> About --> Reset --> Factory Reset:
If the TV has internet access, please check if there is a new version of software updated online or not.
Press the Settings button on the TV remote, then select Settingsà System à About à System Update à Network Update:
If the problem can’t be resolved, please feel free to call the TCL hotline for further help.
