The usual reason that your garage door won't close is that there is something blocking the "eyes" that protect your children, pets and property from being injured by your door. Look for the obstruction. If you find none, then check that the eyes poing to each other. If they point to each other, check the continuity of the power going to the eyes. As a last resort, take a Q-Tip and clean the lenses. In none of that works, it's time to call us at 864-513-1436.