The garage door opener "can't" close by itself. It can reopen itself if the "photocells" are even "slightly" out of alignment. The only way the door can open,(at 2:00 the bars get out??? someone is fooling around??) is if someone has a programmed remote control to your door, or there is a slight short in the wire from the doorbell (wall) button end or the end of the wall button that connects to the back of the door opener. I have seen this. Sometimes they use speaker type wire that has several strands of wire. They may have frayed just slight. If just one strand of frayed wire is just barely touching the other contact. It will activate the door opener. Just a person walking above the door opener can activate the door without knowing. Most of the time they use a single strand wire and this does not usually happen. Lets try this first...Clear your board of all frequencies,(by holding in the programming button on the back of the board, it will be a colored button). Re program your exisiting remote controls and keypad back into the board. Check the wire behind the wall control, check the connection where the wires connect to the back of the opener. Make sure they are connected and are tight and not touching other contacts. There are many reasons for the door to "reverse". The door should "never" close without a command from a remote or wall control.. Dan

Make sure you put the black cup back on the end of the motor shaft and that it is pressed all the way on. Make sure the rpm sensor is plugged in. If none of these are the issue, then you probably did not have the motor shaft pushed all the way back when you tightened the coupler after replacing the worm gear. Loosen that coupler up and from the front of the motor (opposite end in which the coupler is on) push the shaft back as far as it will go. Hold it there while you tighten the coupler back up and then try it.

Actually, I am finding that the top part of the controller may be causing my problem also. I have removed the cover off the top part of the controller to see if that is the problem. There are two tabs on the top of the controller cover that you need to depress in order to remove the cover. It has been about three days now since I removed it and I have had no phantom openings. You can still use the controller. You will see a small blue or green button when you remove the cover. One of the Sears repair persons told me to try that first. If that doesn't solve the problem, then the problem is in the wiring (Staple or something shorting out)and would then have to replace the wiring.

Sounds like your logic board might be going on the fritz. If you think you might want to replace it yourself, I can tell you where NOT to buy it. I recently bought one from Ontario Supply in New York from their web site for $60. Unfortunately, it has turned out to be defective and they won't refund my purchase price even though I sent the defective unit back at my own cost. So, don't buy from them, they don't deal fairly in my opinion. I think you're best off just calling a local repair service and let them replace the board. If you replace the board yourself and it does not work, you're just going to end up calling a repair service anyway. Ontario Supply operates under the following web sites: http://www.wholesalegaragedoorparts.com and http://www.liftmasterpartsonline.com/ In my opinion, you should avoid this company