Our air conditioning stopped cooling a month or so ago. We took it to a local shop and they said the freon was OK and we paid them $50 to investigate further. They said that they thought it was the compressor. My husband asked if they were sure and they said that you can never be sure (implying it was by default). We did not do the repair but are now thinking of it. We did not get anything in writing which was stupid of us but we will go back and ask exactly what they looked at - it is a decent shop but I think there should have been more on the paper than the labor cost to check it out. It would be useful to know what they should have tested. Thanks for any help.