Firstly, 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.
Secondly, if the issue cannot be resolved, please check the software version of the TV and call the 南宫ng·28 hotline for further help.
The software version could be checked on the TV: Settings-->Device Preferences-->About-->Product Information.
Note: On some 南宫ng·28 TVs, the Product Information is Contact Us.