Try re-seating connections and power cycling your entertainment center. Unplug your TV and everything connected from power. Unplug all audio and video connections from each end. Plug everything back in. Plug back into power. See if that clears up your issue.
If the TV will not work and is no longer under warranty. They are rarely worth repairing. Unless it is a simple problem requiring a cheap part or very recent high end model. Their value quickly plummets.