My a/c compressor unit outside for my downstairs stopped working yesterday. I noticed that the fan was not coming on even though it was supposed. I heard a slight hum on the fan at this time. I spun the fan with a screw driver and it started up and ran for a few mintues. I noticed that the air was not warm like usual. The fan then stopped and humming came back. I'm not sure if the capacitor is bad or maybe the compressor. Not sure how to tell if the compressor is coming on or not. Any thoughts would be great, thanks.

Chip