Some of this you can safely check yourself. If the door won't open, look first at the wall switch, the opener's remote batteries, and whether the safety sensors near the floor are aligned and unobstructed - a knocked-out-of-place sensor is the single most common false emergency call we get. If the door is stuck halfway, or one side looks lower than the other, stop there. That's usually a broken or stretched cable, or a spring that's lost tension, and a door under spring load can put someone in the hospital if it's handled without the right bars and clamps. We won't talk you through replacing a torsion spring over the phone, and we don't think anyone reputable should. Where we draw the line honestly: if your opener is original to the house and just needs a new logic board or gear, sometimes replacing the whole unit costs about the same as the repair, and we'll tell you that instead of billing for a fix that won't hold. A repair that outlives its usefulness in six months isn't a favor to you.