I'm trying to fix a fridge/freezer that recently stopped working but still has power. I removed the panel from the freezer and there was a lot of ice build up which I let defrost. I noticed that the little fan which (I think) forces cold air into the fridge seems a bit wonky. It sometimes starts running if I give is a spin to get it started but then stops shortly after. This video shows that: https://youtu.be/ZQMJDpgACQc. Is this "abnormal", it should I look for the source of the problem elsewhere?