Disposal suddenly dead -- no sound, no hum, nothing when you flip the switch? Most likely a tripped thermal overload. Every disposal has a reset button (small red or black button on the bottom) that pops out when the motor overheats or gets overloaded. It trips when you grind too much at once, the disposal jams and the motor stalls, or it runs too long. Resetting takes 30 seconds. Try this before assuming the disposal is broken. If the reset does not fix it, you are looking at a jam, a tripped breaker, or a dead motor.