I removed the shelves, drawer, light bulb, ice maker and back panels to expose the scary stuff. There was a lot of ice build up so I defrosted it. I was determined to resolve the issue myself. My husband was sure we needed to call a professional but humored me in my quest for an answer. I researched online and found that we had an adaptive defrost system. Websites helped me diagnose the problem and guided me on how to test the the Controller Assembly using an ohmmeter. I read a tutorial on how to read an ohmmeter and learned that an open circuit (when the freezer was cold) meant the current could not flow = bad part. YAY! I ordered the part on a Sunday afternoon, it arrived Wednesday and took less than an hour to install and put it all back together. That was the easy part. Diagnosing took longer.