You flip the switch, the disposal makes a low hum, and the blades do not turn. This is one of the most common disposal situations, and most of the time you can sort it out in a few minutes. The steps below move from the safest checks to the ones that need a professional.
Cut the power first
Before you reach toward the drain opening, switch the unit off at the wall switch or pull the plug if you can get to it. Never put a hand or a tool into the chamber while the unit has power. A disposal can start without warning if the switch is bumped or the reset is pressed by accident.
Look for a reset button
Most disposals have a small reset button on the underside of the unit. Press it firmly. If the unit has overheated or been overloaded, the reset breaks the protective cutout. Then try the switch again. If it hums and stops again right away, the reset did not solve the cause.
Free the flywheel by hand
Many disposals have a hexagonal socket in the center of the bottom plate. With the power still off, fit a hex wrench into that socket and turn it back and forth. You are trying to rock the flywheel loose from whatever is holding it. If it moves freely, remove the wrench, restore power, and test it. If it will not move at all, stop and move to the next step.
Clear any object with tongs
Use kitchen tongs or pliers, not your fingers, to remove anything you can see, such as bone, a bottle cap, or a utensil. Keep the power off the whole time. Once the chamber is clear, run cold water and test the unit briefly.
Tell the cause apart
If the unit hums and the wrench frees the blades, the problem was a jam, and it is probably resolved. If it hums and the blades will not move even with the wrench, the motor may be seized, which calls for a professional. If the unit makes no sound at all, check the breaker and the wall switch, then the reset. If the unit turns freely but water drains slowly, that is a clog in the drain line, which is a separate problem.
Questions to ask before a repair or a replacement
Ask the technician what they found and what they believe caused it. Ask whether the repair is worth doing for a unit of this age. Ask what the replacement route involves, including the plumbing and electrical connections. Compare the answers against the typical service life on the garbage disposal page so you can decide whether to repair now or plan a replacement.