I have had a Sony Bravia 46" LCD flat screen above my fireplace (ventless gas log set) for a few years and I am noticing now that the screen has a "heat rainbow" in it that is visible when the screen is off. You can see it while watching TV on a bright day as well. The fireplace was used very often and the TV did get some heat that was constant. I have cleaned the screen with the proper screen cleaner, but the rainbow is still there. Any good solutions?