Why won't my garage door close but nothing blocking it?

If your garage door won't close even though nothing is blocking it, the most likely cause is safety sensor misalignment or dirt, as sensors can detect false obstruction even when path appears clear, preventing closing as safety feature. Safety sensors near bottom of door tracks send infrared beam, and if lenses are dirty, cobwebbed, misaligned, or wiring loose, receiving sensor blinks and opener thinks something blocks beam, refusing to close and often blinking light 10 times. Clean lenses with soft cloth, ensure sensors face each other with no gap, and adjust until both LEDs solid. Check for small objects like leaves or dirt on sensor lens that appear as blockage, and for sunlight shining directly into sensor causing interference, shading sensor if needed. Other causes include travel limits set incorrectly where close limit is too short, causing door to reverse before touching floor, requiring limit adjustment via screws on opener. Door binding due to rollers off-track, bent track, or broken spring can cause opener to reverse when closing because force setting detects obstruction, so try closing manually after pulling emergency release; if door is heavy or binds, spring or track issue. Lock mode engaged on wall console or remote lock can prevent closing. Opener logic board or RPM sensor failure can cause reversal. Try holding wall button down continuously, which overrides sensors and forces close if sensors are issue, but fix sensors promptly. If door reverses immediately after touching floor, close limit needs adjustment.