Freezer compartment still makes ice, refrigerator cools to about 16 deg F (55 F) below ambient. Unit is four years old, in same location and not moved (apart for cleaning). The fan runs (unit is running constantly now) the is a difference in temperature between return and supply to compressor and the coils ect are clean and dust free. Tried switching off and letting unit cool down, no noticeable difference. Seals good and doors close properly.
Sheila, many thanks for information, I will try defrosting completely and see if that helps. Do not know if there are any dampers, the hand book does not mention any. The Model No. is MZD 2766 GEW.