When you say housing I am assuming you mean cover. How old is the opener?

It was installed when I moved in earlier this summer, so I assume it's at least 8 years old. Worked great before the gear degraded.

And yes, by housing I mean the cover.

Ok, on the back of the opener there should be a learn button with a little LED light next to it. Push the learn button and see if the light lights up. If it lights up then your still getting power and something went wrong with the circuit board. If it does not light up then I would double check all the wires going into the circuit board and make sure they are all secured in the harness. I would check and make sure the wires coming in for power are all still connected. I don't have an explanation as to why it worked fine until you put the cover on. Maybe just bad luck. Could have had something to do with the board falling down twice. Let me know whay you find.

Well, doorguy, the light next to the "Learn" button doesn't come on when I plug it in and push it. I also emailed the manufacturer who suggested I attempt to "hot wire" the opener to determine the source of the problem (capacitor, logic board, harness, etc.). I'm no electrician, so what do you think about attempting it? They have emailed me a detailed diagram of how to do it, but I don't know how difficult it will turn out to be. What's your opinion? Also, given that the yellow light doesn't light up with an prodding, does that narrow it down for you? Thanks again for your help.

Todd

No light coming on when you push the button is leading me to believe you have a problem in the wiring harness or still possibly a bad board. You can purchase a power tester at local hardware store for a couple bucks. I would get one of these and make sure I still have power coming into the opener at the other end of the power cord. If you pull off the cover the power cord should be coming into the unit on the back right hand side. I would check that to make sure there is power there. If there is I would follow the diagostic diagram the manufacture sent you. If your not comfortable with electricity, I don't recommend you try hardwiring anything. I can't think of any other normal, easy things to check. If I were there I would swap boards to see if anything changed. If you have access to another board of the same kind you can try that. Otherwise I would be on the phone with a tech myself if I could not visibly see anything else wrong.

Good luck and let me know what you find.

Ordered and installed a new logic board and lo and behold, works like a dream! Thanks for your advice; and I didn't even have to subject myself to the risk of a nice shock while attempting a hardwire! Much appreciated.

Suddenly on my liftmaster garage opener, the power from the big square button on the wall to open the garage isnt working. No light on that button either now, so somehow it must have lost power. The remote control pad opener outside the garage still works. Suggestions on what might have suddenly gone wrong?