When you turn on the garbage disposal, and it produces a buzzing noise but accomplishes nothing, the flywheel inside is probably stuck. If you encounter this issue, immediately stop the garbage disposal! If you continue to run it while there is a jam, the motor may burn out and irreparably damage the appliance.
To avoid mishaps, switch off power to the machine at your home's electrical panel before attempting to fix your garbage disposal. Check that the power is turned off at the electrical panel and that the garbage disposal's wall switch is turned off. You can then attempt to remove the jam. If you feel uncomfortable with the task, ask a professional plumber.