My garage door has power, but it won't open. What could be the problem?

If your garage door has power, indicated by opener lights on and wall console lit, but won't open, problem is likely mechanical or with opener components rather than power, requiring diagnosis of several possible causes. First, check if manual slide lock on door track is engaged, as lock physically prevents door from opening and must be disengaged. Check if trolley is disconnected from emergency release cord pulled, as disconnected trolley means opener motor runs but door doesn't move, so re-engage trolley. Broken torsion spring is common cause, as spring counterbalances door weight, and when spring breaks, door becomes too heavy to lift and opener may hum but not move or may open a few inches then stop due to force overload, requiring professional spring replacement costing 200 to 400 dollars. Check safety sensors, as misaligned or dirty sensors with blinking LEDs can prevent opening in some models, so clean and align. Travel limits set incorrectly can cause opener to think door is already open. Opener logic board failure, stripped drive gear, or motor failure can cause no movement despite power, with motor humming or no sound. Door off-track, rollers binding, or broken cable physically prevents opening, so try opening manually after pulling emergency release; if door won't lift or is very heavy, spring is likely broken. Remote battery dead or lock mode engaged on wall console disables remotes, so check wall switch, as if wall switch also fails, problem is opener or mechanical, not remote.