My friend has a ariston kve 160l built in fridge about five years old. It had been cooling down to around about 3 degrees but recently it only goes down to about 5 degrees. I am aware of all the problems with the latest fridge/freezers not cooling to the ice build up problems but this is fridge only and on a normal themerstat. moving the temp selection knob does not seem to change the temperature at all. I thought about changing the thermastat but in past experiance they either went or didn’t go at all. this one is going but just not getting cold enough. my friend assures me that the back panel is icing and then defrosting like it normally did. Could it be the compressor on the way out ? I would be grateful for any help Brian