The broken device is used in the Mourning's End Part I quest. It is given to the player by the Head Mourner in West Ardougne and the player must have it repaired by a gnome who is being held captive by the mourners. The gnome will repair the device, turning it into a fixed device, but only after the player has tickled his feet with feathers and given him some toad crunchies.
The broken device can be re-obtained from the chest in the Head Mourner's office. To get it fixed, you will need a tarnished key, a piece of leather, a magic log and some toad crunchies. The gnome will still repair it after Mourning's End Part I is complete, but it is impossible to do so after completing Plague's End.
The device was broken by Nissyen Edern when he attempted to fire vials of dye at the sheep in an attempt to dye them after wasting his original ammunition.