If the temp in the unit, is 9, a few seconds after you set the unit, it will revert back to displaying the internal temp., If it is not goinging below 9, some other problem, If auto defrost, check defrost htr is not stuck on, you would need to undo the panels in the back of the compartment, You could unplug the htr, and see what happens after that, if temp drops htr cct fault, could be pcb or other. Unit would run fine for days with htr unplugged. Until it started to ice up again
SD, August 2012