[Sierra]

We have an insinkerator. It hums and we have tried using the allen wrench. We've also cut the circut breaker and tried the reset button. All we get is a hummng sound. The only time the reset button worked was when we left the switch on and it automatically stopped humming. Then we cut the circuit breaker and the reset button was enabled. Otherwise it was of no use. However, the disposal still just hums and nothing spins. Both the blades and the base unit which grinds rotates freely with no problem. Can we spare this unit or do we have to replace it?? Please help!