Perhaps the following will help you find a model number.
Find your model number - AppliancePartsPros.com

The year does not really help as they make many different models.

Is the compressor running?
You can usually hear it but also should be able to feel it vibrating.

If it is running, does it run continuously except when the unit goes through e defrost cycle?

If it runs continuously remove the cover in the freezer so you can inspect the evaporator/freezer coils.

If they are clogged solid with ice/frost then you have a defrost problem.

If there is no frost or just frost in one area (usually where the freon enters the coils) then it is a sealed system problem.
Make sure that the compressor has run for about an hour when doing this. If you checke them shrtly after or during a defrost cycle you will end up with the wrong diagnosis.