I have a PT406LED (generic Chinese badge brand TV from Australia). It overscans a fair bit and there is no setting in the regular menu to stop the overscan. I have accessed the service menu and fixed the overscan there however when I change channels or inputs or turn the TV off, the default overscan settings are reset. How should I go about saving the overscan settings in the service menu. For context, I accessed the service menu by pressing source+2580.