A disposal that hums without turning is jammed, not dead. A disposal that leaks at the flange usually is dead. Two very different visits.
The hum means the motor has power and the plate will not move. There is a hex socket in the centre of the underside of most units, and a quarter turn each way with the right key frees the majority of jams. The red reset button on the bottom then brings it back.
If the reset trips again within a minute of running, or the unit is silent with power confirmed at the switch, the motor windings are usually finished and replacement is the honest answer.
We replace and install as well as repair, and we will check the dishwasher drain connection while we are under there, because that knockout plug catches a lot of people.
Fibrous vegetable waste, coffee grounds in quantity, rice and pasta, and grease. Cold water while it runs, not hot.
Often not. Try the hex key and the reset button first. If that clears it, you have saved yourself a visit, and we would rather tell you that.