My refrigerator has all of a sudden stopped cooling to the proper temperature. i have read some of the other threads already pertaining to this particular problem and i want to try to find the problem myself. when i look at the back of the freezer, i notice that the wall is frosted over. i have already removed all of my food and have unplugged it. should i let it completely thaw out or what should my next step be?

Your next step should be ohming out the defrost heater. If the heater does not ohm out, replace it. If it does, then it would most likely be the motherboard. Make sure you test the heater, with the power the refrigerator unplugged. Tom ApplianceEducator.com