AT wrote:
I have a Lennox 10 ACB Compressor system. I noticed today that the Air
compressor (external) was making a humming sound and the fan was not
working. The rest of the Air Conditioning system seems to be working
fine.

Any suggestions on how to resolve the above issue.

I'm guessing the start capacitor is kaput.

1. Turn off power.
2. Take several pictures of wires connected to capacitor(s)
3. Remove capacitor.
4. Take capacitor to A/C parts store and say "Gimme one like this"
(Higher voltage okay)
5. Install new capacitor
6. Turn on power.
7. Does it work?
7a. Yes, you're done
7b. No, call reputable A/C tech