There are several reasons why a garage door opener may stop working, including: 

• Batteries: The batteries in the remote may need to be replaced. 

• Power: The opener may not be plugged in or the breaker may have tripped. 

• Motor: The motor may be old, overheating, or dying. 

• Wiring: The wiring may be faulty. 

• Components: Some components may be worn out or broken. 

• Force limit setting: The force limit setting may be too low, preventing the door from fully opening. 

• Obstructions: There may be obstructions in the mechanism or on the track. 

• Safety sensors: The safety sensors, also known as photo eyes, may need to be inspected. 

A broken garage door spring can prevent you from operating your garage door normally. Here are some signs that your garage door spring may be broken: 

• Loud noise: You might hear a loud popping sound when the spring breaks, even if the door doesn't fall. 

• Door is off track: The garage door may be off its tracks. 

• Door doesn't move: The garage door opener motor may be running but the door isn't moving. 

• Door is misaligned: One side of the door may raise more than the other. 

• Gap in the spring: The spring may have a gap in the coils, which means it's worn out and can't move the door. 

• Top panel bends: When you try to open the door, the top panel may bend. 

It's usually not safe to try to manually open a garage door with a broken spring, and it's often best to wait for professional help. Replacing garage door springs is usually a job for a professional. When one spring breaks, it's often recommended to replace both springs.