Why did my garage door all of a sudden stop working?

Your garage door may have all of a sudden stopped working due to sudden failures that are common with mechanical and electrical components, including power loss, broken spring, sensor misalignment, or opener failure. The most common sudden failure is broken torsion spring that counterbalances door weight, as springs store high tension and can break with loud bang, causing door to become too heavy to lift and opener to hum but not move, requiring professional replacement costing 200 to 400 dollars. Power outage, tripped breaker, or GFCI tripped can cause sudden stop, so check if opener lights are on and outlet works. Safety sensors can suddenly become misaligned from being bumped by car, lawnmower, or foot traffic, causing LEDs to blink and door to refuse to close, so clean and realign. Emergency release cord may have been pulled accidentally, disconnecting trolley and preventing opener from moving door, requiring re-engagement. Remote battery can die suddenly, and lock mode on wall console can be accidentally engaged, disabling remotes, so check lock button. Logic board can fail due to power surge, especially after storm, causing opener to have power but not respond. Door can go off-track from hit, causing binding that stops operation. Cable can snap suddenly, causing door to jam. Extreme cold can cause lubricant to thicken and door to bind. To diagnose, try manual operation after pulling release; if door won't lift, spring likely broken. Unplug opener 30 seconds to reset.