A: Make sure all cables are firmly connected into your television and your external AV source. After you have made all connections, make sure the sound input matches the video input. If you are trying to view a TV station, switch to another station because some channels may be having broadcast difficulties. Check to make sure the brightness/contrast settings are correct by entering the main menu and adjusting.
If none of this works, reset all your connections. Power cables or HDMI cables can come slightly loose overtime and lose connection. Start by unplugging the power cable from both the TV and the wall outlet. Next, unplug the HDMI cable from the TV and your media player. Ensure that both are firmly plugged back in; this will reset the connections. You may also try fully unplugging the power from you media player and re-plugging it back in.