This is what happened. My youngest daughter was in my shop with me and I was about to use the bandsaw. As I was setting up for that, she put on her safety gear (ear muffs and goggles). I was about to turn it on when I checked the speed setting and realized that the last time I used it I had left the speed set too fast for the bandsaw. I disconnected from the bandsaw, turned it on and slowed the speed down, turned it off and hooked the bandsaw back up. I put on my ear muffs, and right as I flipped the switch, my daughter said something to me. I flipped it back off and she repeated what she said. I turned it on again, and it just hummed (and sorta growled). No turning.
I started checking everything. Everything turned freely. I pulled off the belt cover and inspection hole cover. Everything looked fine. Tried different electrical outlets on different circuits. I put the sanding disc on, applied power and turned the disc by hand to give it a boost. No change.
I took the motor off the headstock and set it on a bench. Applied power and just a hum (and sort of a growl) and very slow turning of the shaft. The shaft feels fine when turning it by hand. The bearings feel fine and make no noise.
What did I do? Did the quick on/off fry something? It worked just before that.
(Sorry, had to go there!)
) then grab a mallet and make sure the thing is awake. Only then do you attempt any kind of testing. 
Yes they do fail but not nearly as often as guys like to think. Never doubt the capacitor until you have checked the starter switch. 
