It looks simple and neat, though it's became dysfunctional after being installed for a week. Very likely it's stuck at a place relating to the reverse function: no matter which button I pressed, it just tried to reverse direction and then was stuck there without moving. Did this happen to anyone? Any tips to fix it (because it would be nightmare to un-install and return it, and get a new one and install it again, given the implications for time and money, sigh) if possible ??