I had the same problem, the top plate with the buttons came off. Then after 2nd fall I could get to the gear that turns the light. After following the guide here I think that your problem is that the ribbon cable that is up in the gear assembly has come off. I worked at mine for like 1 hour but could not figure out how to get the ribbon cable to reconnect on both sides. You will know if this is what is broke by the fact that the bottom light near the plug will be on, but the unit will not respond. I finally broke down and got another one.