How can I fix my In-sink-Erator Badger 5/8hp garbage disposal?

The disposal (60th Anniversary Heavy Duty Edition) recently made a strange low grinding noise and the blades were not operating. We flicked the switch off and then back on and it did no longer made a noise. Then, we hit the reset button on the unit and on the plug and then replugged it into the wall. It then made the low grinding noise again but the blades continue to not work.