It could be the chip itself, or the main board. Without being able to inspect the unit, I'd be hard-pressed to offer a diagnosis. If you'd like to have a service technician take a look, try calling 800-SAMSUNG. Typically they can dispatch a service tech to you in your area.
Of course right before the Superbowl, my 61" hln617w all of a sudden has groups of thin vertical black lines all the way across the screen on groups of 8 with a space of the same width between them. Does anyone have a clue what this is?