Air Conditioning - A/C stopped cooling, outside unit hums

I have a Goodman A/C, about six years old. It was cooling fine until last night. Now when the outside until comes on, there is a loud hum, and the fan speeds up very slowly. It eventually gets up to speed, but the hum remains and the unit does not cool. The fan does not seem to be binding, as it spins freely.

On a side note, in the past week I've noticed a strange smell, almost like the smell in a hair salon, whenever the A/C was running. May be unrelated?

I'm thinking the compressor is shot, but could it be low freon, or a bad starting capacitor on the compressor?

Thanks for any help!

I'm thinking the compressor is shot, but could it be low freon, or a bad starting capacitor on the compressor?

From what info you give it can be any of it. Dont think low freon. Then also can be cap for the fan motor. That smell you say can be the fan motor. You have to call a tech and go into the unit to find out what is what.

ED