Hi Ale, I will try to give you some more positive advice, there are several reasons for a device to stop cooling even when the compressor is running. The first and basic thing to diagnose is to check the pressures, if the low is very high, the cause may be due to the blocked or blocked expansion valve. The second cause can be the dehitrador filter exhausted or clogged causing the same effect as the expander, lack of refrigerators. Questions how to diagnose, do you have pressure gauges? Do you have knowledge about A / C? If so, you have it or you get a pressure measurement and see.