Fan has power and when I turn it on it just hums. Without the blades it works just fine. THe light works OK. I have removed the packing nuts. Is there something I'm missing?

Check the direction switch is in 1 or the other positions, Do the blades spin freely by hand, try other speeds.
All else, verify you have good power to the fan connections or temporarily connect to the known good lights wire in the canopy.
If it just started and direction switch and voltage are good, it may just be the capacitor.