I'm a DIY kind of old gal with no real experience but I spent a lot of time reviewing the available videos. I was able to easily order the proper parts and finally install them (often reviewing videos again). I replaced the interior fan. I also replaced the interior heat element, but I don't think that was the problem. The fan had definitely quit working. It has been almost 3 months when the fan started a grinding noise again. I ordered another fan, but in the meantime the grinding noise stopped and the frig still cools properly so I've left it alone. (I'm very short, so working inside the frig is not easy for me.) Conclusion: I believe there was another ice buildup which came in direct contact with the fan until it melted. My frig has a lot of traffic that may interfere with proper defrosting, or as some have complained, it is a Samsung problem.