I have a Mistral 8956p which works very well except that the fan noise is driving me mad. When it cuts in, it sounds like it’s vibrating against the inside of the case. If I open the fridge door it stops, but resumes when I close it. Sometimes, if I nudge the fridge at the top front the fan continues to run but the noise stops. Is this the fan in the back of the freezer or another one. How do I get to it to shut it up?