** [the disposal just hums and nothing spins.] The allen wrench turned freely in both directions. **
Than there is likely a problem in the motor windings as HayZee suggested or the start switch mechanism. Have you ever noticed any leaking from the bottom of the unit? Any signs of rusting there?
A motor winding problem would not likely be worth having repaired, there's a slim chance a switch problem might me
if it is a near top of the disposal model. If the disposal is one of the cheaper models it is unlikely to be worthwhile to have repaired with your stated symptoms and it's likely a good time to shop for a replacement.
You can find some disposer purchasing tips at the following link:
LINK >
The Purchase: Productopia Tips: Disposals
PS. Check the unit's warranty. Some top of the line In-Sink-Erator models had up to a 10-years warranty on them. You may be able to date your unit at the following link:
LINK >
How old is my appliance?
JFYI
Dan O.
www.Appliance411.com
The Appliance Information Site
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