You might need to adjust the limit screws if the garage door won't close all the way. The screws have contacts that let the garage door opener know how far to open or close. It is possible that a garage door refusing to close is a bigger issue than just fixing the sensor, cleaning the tracks, or resetting the travel/limit setting. If it isn't one of the common issues, it's probably time to call in the professionals.
The limit switch needs only a flathead screwdriver if your garage door isn't staying open or closed. LiftMaster has a resource that explains how to adjust a limit switch.
The garage door's weight is counterbalanced by the springs of the door. Both automatic and manual garage door systems feature these springs. Two springs run over the width of the door, while two extension springs lift and lower the door.
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 the breaker panel.
Garbage cans, shovels and even mice can cause damage to the wiring. It doesn't take much for a small electrical signal to cause the opener to open. The opener's logic board or the motor unit itself could be to blame when the door begins to descend on its own. Like your travel down setting, your garage door opener's limit switch governs where your garage door stops.
There can be pressure and wear on door tracks. If your garage door isn't working, call a service to get the tracks replaced. The shut reverse, where the door closes and then comes back up, is a wackier malfunction. Problems like this are often caused by a misadjusted limit setting on the opener. A dead transmitter remote is a minor problem but a common reason your garage door won't open often.
If it closes before the set distance is met, it will go back up to prevent damage or safety threat. Your garage door components can change due to weather changes. The issue can be fixed by adjusting the travel down setting. Residential electric garage door openers that were manufactured after 1993 have two safety mechanisms that operate while the door is closing. Since that date, all garage door openers include door sensors that prevent the door from closing until all obstructions are out of the way. A misalignment of the reversal system is the most common scenario. The door opener interprets as an object in the way of the door's descent if the two sensor housings are out of alignment.