Need more info.
Is the freezer compartment all frosted up?
If so, and the Evap. fan motor is working, then you have a defrost issue. Either timer, termination stat, or heater element.
If your compressor is trying to start, but humming and clicking, then it is bad.
If your compressor is running but quieter that normal, then you most likely have a sealed system issue.
Is the condenser fan in the back working?
Condenser coil clean and not full of animal hair?