Michael - I used this answer for another question but it sounds like it could apply to your issue if as you mention you shredded a lot of papers in one go...
"It sounds like you ran it for an extended period and the teeth on the plastic gears inside, that transfer power from the motor to the cutters, melted. That's what happened on mine anyhow - you need to check the specifications - home office models are designed to be used e.g. for 2 minutes continuously - then rest for 10 minutes etc. - the plastic gear teeth heat up and soften - if you keep pushing paper through the teeth just strip off and you lose traction. Sometimes the reverse function can seem to keep going a little longer than the forward function for some reason. Good luck finding parts for it - you're better off buying a new unit - especially if it's a made in China model (aren't they all) - the distributors just ship boxed units - if you ask them about spares they act like you're crazy. It's a bit sad having to junk an otherwise working unit for the sake of a plastic gear wheel but that's the way they keep the costs down unfortunately..."
Hope yours isn't as terminal as mine.
I'm looking to get another unit and I'll try and shred my stuff as I go - not save it all up and then overload the machine again... ;)
All the best,
Steve
Steve, September 2008