From what you're saying about the freezer being cold but the fridge isn't. And the noise when you open the door etc. I would agree with you that the fan that sucks cold air from the freezer to cool the fridge (this is how a frost free appliance works) is not working. you can check for continuity between the connections on the fan to check it ....... if you need more advise let me know - regards Neil
Apologies - but the obvious solution would be to replace the inoperative fan.
It seems the professional has left this conversation. This happens occasionally, and it's usually because the professional thinks that someone else might be a better match for your question. I've been working hard to find a new professional to assist you with your question, but sometimes finding the right professional can take a little longer than expected.
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Thanks for your patience,