Your disassembly video was excellent. I coulnt figure out how to take it apart before seeing the video. my dc21 motor head stops after a few seconds, especially under load. It spins free and motor is not hot? Any idea? I think due to me being careless, I now have no power to the motor head. The motor head does turn if 240 volts applied to the two wires, and the tried switch wire is working fine. I have another dc21 (not motor head) that turns on for a fraction of a second, then stops. Im guessing its the power switch. Any ideas?