Just had power outage and fridge hasn't cooled since coming back on. Freezer (on top) is 21 degrees and fridge (below) is 50 degrees. I checked fan in freezer and it wasn't running, so figured that was my problem. I took it out and checked to see if it was getting power and it was, so I put it back in and now it's working. There was absolutely no ice build up and no obvious reason the fan wasn't working. The key is the fan is working nicely. Lots of airflow, but it seems to be blowing into the freezer. Not much going into the fridge. There is no blockage between the freezer and fridge. I even took the vent inside the fridge out to get as much flow as possible into the fridge. Could the fan be running backwards?