Hi
Mines did the same today, jammed solid, and I took them back to Homebase under warranty. Unfortunately I did not keep the receipt but have used my bank account to trace the purchase, so it is back to Homebase tomorrow.
Did not get manual with the box.
Sorry, not much help, but at least I now know not to waste money on some of these cheap Chinese imports.
Good luck with yours.
Mike, July 2007