I have a fellowes ps-62C and the same thing happened to me, I have replaced the machine once and it has happened again, on both occasions I opened up the shredder and found that the cheap plastic that surrounds the blades was broken and stopping the blades from functioning. Workied fine after putting the plastic in place, but there is obviosly a design fault with the version I have. Might be worth opening it up to check the wire.
J Thomas, December 2007