Product review (5 stars): Replace this part too, not just the coils and fix it once and for all!
If you have the infamous "dripping fridge" or frozen coils in your defrost on a Samsung refrigerator, this is the fix.  There are a few parts to get from other sites, like a new defrost coil and a new temp sending unit and then swap this board out.  Simple to install, a few screws at the back lower part of the unit and you're in.  Then a few more to take the white plastic housing off the left side of the fridge (from the back it would be on the right side).  Got me going.  For what its worth, the fridge has a little metal riveted tab that is supposed to act as a defrost for the water drain.  In my opinion, this part is too short and is the cause of this whole mess.  I used some metal strap and an aluminum rivet (you get these and a rivet gun at a car parts store for under 10 bucks) and I made a longer tab to go into the drain.  When the defrost coil comes on, the heat is then carried through this little tab and keeps the drain from icing up, hence your fridge stays dry!