Believe it or not, I had a similar experience. Mine quit working as detailed above so I sent it back and got a replacement. When I tested the new unit (different flashlight) it began t smoke behind the lens, staining the reflector. After two failures in a row, I requested aa refund, which I have been told I'll receive (just sent it back tuesday).
Hearing that I'm not the only one who has had multiple failures, I question if this is a design problem.
Good grief... looks like this mess is really gonna get messy