Figuring Out What"s Wrong With Your Garage Door
Almost all garage doors slide up and down on metal tracks attached to the garage walls. The entire mechanism operates on one or more tension springs which you definitely need to treat with care. Lots of times nothing is wrong with the door itself; instead, it's the tracks. They may have gotten dirty, blocked, dented or damaged, dry, or moved slightly out of kilter which won't allow normal operation. It's a simple matter to clean and oil the tracks in order to allow everything to function. If those techniques don't work, then it will be time to move on to another cause.
You may have to get out a level and check to see if the tracks are in alignment. If you find discrepancies, you can correct them by loosening the screws on the mounting brackets. Once you've loosened them you can gently tap the tracks until your level shows you that they're where they're supposed to be, then re-tighten the hardware. It could just be that the screws have loosened allowing the tracks to become a bit loose. Tighten everything up, and you'll be ready for business.
Most people these days have automatic garage door openers, because it's more convenient than opening and closing the door by hand. That is, it's more convenient until something goes wrong with it. Most likely you'll reach a point in time when you'll need to replace the opener, and you'll find that it isn't a difficult job if you carefully follow the directions. If you already have an opener, you can install the new one in the same spot. If it's a brand new addition, you'll need to measure to find the right place to locate it. You also need to mark a place above the door that will support the front end of the rail. From this point, the manufacturer's instructions will lead you through the best way to install your new device.