If the compressor is running and there is no frost on the evaporator coils there's a sealed system problem. The sealed system consists of the compressor, condenser, evaporator, heat exchanger, filter/drier and refrigerant. Common problems with a sealed system are bad compressors, refrigerant leaks, and system restrictions. Sealed system repair costs will often exceed the machines value.
Check your owners manual warranty, some models have up to a 10 year warranty on the compressor, and 5 yrs. on the sealed system, which includes the compressor.