My Central air quit working yesterday morning. Thermostat set at 78 indoor temp at 86. When I turn on the unit. I can hear the blower come on and air comes out of the vents. When I go outside after I turn on the unit, I can hear a buzzing sound. I used a screwdriver to spin the fan and it started. Now with the unit running, outside and inside but there is still warm air blowing out of the vents. I looked at the capacitor, the top seems a bit rounded maybe bulged but I don't know what a new cap looks like. Any ideas?

You my friend I think have found your problem
Replace you cap with and exact match
They are not/should not be rounded or buldged at the top

Replaced capacitor. The unit started cooling immediately. Seems like it should be colder though. Thanks for the quick reply!