Why the door gets checked before the opener
An opener is only designed to guide a balanced door; it is not supposed to lift the full weight of a failing system. If the door is heavy by hand, binds in the track, or drops when released, installing a stronger opener only hides the real problem and can wear out the new unit early. Mars checks balance, rollers, hinges, spring tension, sensor alignment, rail condition, travel limits, and force settings before deciding whether repair or replacement is the honest recommendation.