I have one of these and have problems with it, The fridge has been alarming and was not working correctly.
On investigation the top of the fridge on the pipes was frozen solid, I have defrosted this but noticed the fan does not come on and when turned on the long rotating drum with the fins on stops turning after about 30 secs, this is also shown on the air flow display on the front of the fridge, the display also says high hum.
Is this a fan problem or iare other forces at work?