Terminator, thanks, I appreciate and sort of understand what you have explained. I know very little about electronics but yours is a great expanation. I know about the three little nuts you talk about. I suspected that is what held the assembly in. And I appreciate the warning about not dropping one of them. On an 840 I had I was changing a bulb which was about a 5 min job and I dropped a similar nut that took about an hour to figure out how to find it and then fish it out.