That photo sensor in these machines makes me a KILLING. Samsung pays very well for a 20 mins job of swapping out those sensors, but as blackcat said, you do wanna load the smartpanel on your computer. There have also been some major defects in the SMPS board / fuser unit in these machines I've come across. And be very careful when attempting to remove jams from the fuser unit because you can end up breaking off the pressure lever / connector on the left side.
