1. Check all cables are securely connected to both the TV and the device supplying to it.
2. Check your device source selection (TV input).
3. Check to see if the TV is set to the correct input source.
4. Configure the settings of the device providing to the TV (if applicable).
5. Update software of the device providing to the TV (if applicable).
6. Restart or reset the TV.
7. Restore your TV to its factory default settings.