thank you Samuri. There was no sound at all. I just took off the thermostat and tested it with my multimeter and the thermostat is working, so I imagine it must be the compressor or fan? The thing is, the fridge is in such good condition, just looks like new so I am loathe to write it off.
It depends on what terminals you checked as it stays live on 1 terminal for the light.
if both fan and compressor not working it should be the stat faulty.
Thanks again Samurai. On the thermostat tested terminals 3 + 5 (both were brown wires) gave me a reading; and terminal 4 (black) with either 3 or 5 gives no reading. I checked the relay pins on the compressor and there is no reading at all in any combination.