Seems to be fairly common issue...my fridge portion is not cold, but the freezer (bottom) is working fine. I take the panel off the back of the freezer portion to find there is tons of frost on the coils. I defrost everything with a hair dryer and it works just fine until it frosts up again to the point where aparently the damper is not allowing the cold air to travel up into the fridge portion. My question is this: what are the possible issues? I am assuming it's the defrost heater that is no longer functioning...how do I (A) find it/get to it (thru the freezer portion or from the back of the unit), (B) test it to determine if it's good or bad, and (C) get a new part? Thanks.

Chris