I am not conversent with this model. However, if it has two compressors, one for the fridge and one for the freezer, you will probably find it is a problem with the compressor. It may be shot, or require re-gassing, which requires specialist equipment. If it has only one compressor serving the fridge and freezer, consider adjusting the thermostat and investing in a fridge/freezer thermometer. Check the temperatures of both. Freezer should be at least -18 degrees centigrade, fridrge between 2 and five degrees.
Oaul Higgins, July 2005