Samsung LE26R41BD?

There is a fault on this set which prevents access to the tuning menu in DVT mode. Also the 'Plug and Play' option in the menu is greyed out. Every time the set is turned off, all memory of the settings for contrast, brightness etc is lost with settings returned to 0. I have tried 'reset', but this hasn't solved the problem. Not sure if this is a fault in software or hardware! Is there any solution short of replacing the main board?