What
Phoenix is it?
Compressors are supposed to hum. They are not supposed to buzz or ring.
Depending which model you have I would have you check the microfarad measurement of you capacitor and make sure it is within the plus or minus 5 of stated on the body of capacitor.
If it is a 35uf I would jump it to a 45 right off and this will help the compressor significantly start and run easier. Don’t go higher than 45 though as damage can and more than likely occur
There could be other issues as well. Good thing is, that you compressor is trying to start so you don’t have a Freon loss issue as your pressure switch is satisfied with enough pressure to call for the compressor to fire.
Could be a wire is shorted or cut, could be the start winding is bad or the run winding is bad or could be as simple as simple as you start or run capacitor being damaged.