Garbage cans, shovels and even mice can damage wiring closer to the photo eyes. Since the wiring is low voltage, small electrical signals can cause the opener to run. The opener's logic board or the motor unit itself may be to blame when the door starts to descend on its own. Like your travel down setting, your garage door opener's limit switch governs where your door stops when raised or lowered.
The limit switch needs only a flathead screwdriver if the garage door isn't staying open or closed. LiftMaster has a resource that explains how to change a limit switch.
Universal garage door remote controllers can work on many openers. When the opener makes a humming noise when prompted but won't open, it's a common mistake. A new opener is often the only way around a stripped gear. Manual activation is the only way to use the door. The replacement of your opener should be done by a garage door service professional. If your house mate hits the remote button while you're working, you won't lose a finger.
It can be caused by pressure and natural wear and tear. If your garage door is malfunctioning, call a service to have the tracks replaced. The shut reverse, where the door closes and then comes back up, is a wackier malfunction that occurs with some doors. Problems like this are caused by a misadjusted limit setting on the opener. A dead transmitter remote is a small problem but a common reason your garage door won't open often.
You can replace the batteries if the garage door remote doesn't work. An electrical surge, even a small one, can cause a breaker to trip. If the breaker that powers your garage isn't in the "On" position, it's time to check your home's breaker panel.
When the garage door keeps going back up when you try to close it, it's a problem. The logic board in your garage door is similar to the logic board in a computer. The logic board is the brain of the garage door opener and can wear out over time.
You should check the wall panel near the entrance of your home to make sure that it has been corrected. The open and closed limit settings are found on most garage doors. When the garage door is completely open and when it is completely closed, these settings tell you how far up the track you can go. The garage door stops when it reaches the open or closed limit. If your garage door opens by itself after you close it, you may have to change your closed limit settings. If the settings are too high, the opener will think that a door has closed too early when it touches the ground, and will mistake it for an obstruction.