I went on line and read your advice page. Based on that, I removed the damper assembly (six screws counting the miserable light fixture) and found the damper door broken as predicted. I went back to your page and ordered the new part. Nice breakdown to get number.
After that, I disassembled the damper assembly, found that the ABS plastic damper had broken from the actuator probably as a result of fatigue from cycling back and forth for twelve years. I used super glue to re-attach the damper to the actuator, then, once in place, I used a soldering iron to melt the ABS a little bit in hopes it would hold the damper until I got the new part. I put it all back together and it worked, or at least it worked after I took it back apart, oriented the damper to the actuator properly and put the fan back in correctly. Mark things as you disassemble if you try this or you will get them backwards too. Anyway, this "fix" worked for the few days until I got the new assembly. It was still intact when I took the damper assembly off to replace it but please, the glue and melt trick is not a permanent fix. I've tinkered with broken ABS before and am yet to find a way to repair it permanently once broken. This fix will get you out of the "woods" for a few days but order a new damper assembly and replace the "fixed" one as soon as it arrives. You will save yourself time and money not to mention frustration.
I installed the new assembly when it arrived. It fit nicely with no problem and it works fine. Job done. Refrigerator side is cold again but not freezing like before. Job was easy. Thanks.
Another lesson. During removal of the damper assembly, the plastic shield that goes below the damper assembly must be unsnapped at the break between the shield and damper assembly by snapping outward away from the damper assembly. It then pulls down to unsnap from the back of the refrigerator. The shield beside the water filter unsnaps away from the damper assembly and then can be pulled out of a snap on the refrigerator wall on the opposite side of the filter. Also, check the cold outlets on the upper sides of the new assembly.. My old one had an outlet on both sides, the new one only had one on one side and a plug on the other. I removed the plug and installed one of the outlets from the old assembly in its place. Again, easy job. Thanks again for the advice from your web site and the quick delivery of the part. I hope this helps some other DYIer.