The following are the usual culprits when your garage begins experiencing problems:
The rollers become flattened from extensive use, which causes the garage door to lose its momentum and eventually come off of its tracks.
The track becomes misaligned or bent, which prevents the garage door from gliding smoothly and thus, becoming stuck.
Weak springs that break down can cause a garage door to become unbalanced and fall apart entirely. Additionally, if tension rods and springs become corroded, they will no longer function.
The garage door opener itself can be the source of problems if there is a short circuit caused by moisture, rust, or frayed wires.