I have an identical problem - I bought the Zanussi second hand - and transported it on its side (so no damage done to compressor etc) I then stood it upright for 12 hours before switching on. The freezer works - but the fridge part remains warm! Yet there is only one compressor.
can you hear the fan running in the freezer compartment?.the fan blows the cold air up a ducting at the back and into the fridge compartment.if you have a model or pnc number i might be able to help you more