I used the sprocket about 3 times when I bought it. Tried using it a couple of weeks ago which was about a year plus since I bought it. Completely dead. Red light flashes on and off. Got on to this forum and tried the options quoted there. To no avail. Contacted HP themselves and they could do nothing bar offering me a partial discount against a new one!!!!! The warranty was out by a couple of months on the product. Got on to my local repair shop and they could do nothing either. Told me this often happens on like small products. Not much use to me. Completely and utterly dis-satisfied. I should be offered a new one.