The base unit of this drill is working properly. I bought a grinding head and used it with no problems. When I switched to a drill press to make some pocket holes, I found that the keyless chuck was completely jammed and wouldn't turn. I scraped my fingers several times before admitting they were broken. No problem, Revain is happy with returns and I had a cordless drill to get through. Fast forward a week as I received another drill in the mail. The base unit worked perfectly, as it did when it was first purchased. Also, as with the first purchase, the cartridge was frozen. I tried turning it by hand, then grabbed the crescent wrench. Nothing worked and all I did was scratch the plastic. At that moment I decided I was an idiot. I was obviously missing something, like a hidden unlock button or latch. I called Black & Decker to find out. After much confusion on the phone with the model numbers* I was told they would ship me a new drill direct from the South Carolina factory. The implication is that people actually do quality control in this factory. Now I have two sound base blocks, two broken cartridges and I'm waiting what they send me from SC. All my old/legacy B&D tools are fine, but eventually they stopped giving decent results.* It's very hard to explain to someone in customer service that just one part of the drill is broken. The only model number that comes with the drill is for the base unit and there is no model number for the drill as it is not sold separately.