A garage door is something that you open, not from the side like your typical house door, but from the bottom upwards. It uses a sliding or vertical swinging door concept that uses multiple sections all bundled up together and resting on a spring tension mechanism. This mechanism is the main reason why it automatically springs upward once opened and curls snugly when the door is fully swung open. But all mechanisms are prone to failure one time or another, and learning how to repair garage doors would always be necessary in the long run.
Which part of the garage door mechanism is faulty? This is the first thing that you should find out when the garage door isn’t working properly. You can test this out by attempting to open or close the garage door and observing the door mechanism while it is open.
Close the garage door first to let the metal track uncurl itself from the mechanism. Check if the metal tracks if they are rolling smoothly. If the problem is in the mechanism itself, observe the parts that are not working properly, rearrange or replace the parts, and try testing the garage door again. If you see that the metal track itself is out of place, carefully remove the track from the mechanism, and reinstall it again. If you see small repairable dents in the track, try pound them back into place using a mallet. Finally, if the tracks are already in bad shape and are unable to function properly no matter what kind of fix you do, then consider replacing them with a new set of metal tracks altogether.
If you see that the nuts and bolts are in place and the track is still in pretty decent shape without too much deformation, then the problem probably lies in the friction of the mechanical parts. Try to apply lubricating fluid to fix this problem. Needless to say though, it would be a lot easier (and a lot less messy) to apply the lubricating fluid while the door is closed and the metal tracks are unrolled.
Try to check and see if there are any mechanical parts that have become loose over time. Be sure to tighten and rearrange each of these parts properly, and to re-check the door again if it would work fine after fixing these parts. If you see one side of the door malfunctioning, or sagging due to the loose or misplaced parts, make sure to reinstall these parts properly again. There are some parts that have become completely unusable over time (old hinges, very rusted bolts), you must also be able to see these parts and replace them accordingly.
So, as you can see, there is practically no need to replace you garage door immediately after it got broken, you can just repair garage doors first. You just need to see what went wrong in the mechanism. Sometimes, it is the simplest of mechanical problems that causes your garage doors to malfunction.