Well the fault warning being referred to is exceptionally unusual because there is nothing of an USB nature associated with the TV, this being the case a certain fault finding procedure has to be gone through to determine whether or not the warning on the screen is originating from within the set for some obscure pre-set fault code programming reason, or its actually coming in via whatever equipment is connected to the set.
If you are on a cable system the next obvious test would be for the cable link to be disconnected whilst the warning is on the screen (without touching anything else) and observe the result, like does the sign vanish? and if it does is the TV operational as far as being able to get a menu (any!) on the screen, or is it locked up.
