it probably overheated. is this a battery operated motor? or is it plugged into the wall? if it is battery operated, then it probably wasn't a fuse... but if your plugging it into the wall, then it could be. maybe the adapter your using is giving too much electrical current. although i don't think this would have a fuse in it, and if it did there shouldn't be that much smoke... you might have left it on and it got overheated. unplug it, or take the batteries out, and give it some time to cool off. i doubt its broken, but it might have gotten overheated a bit. i could give you a definite answer if you told be WHAT its power source is.