Almost every confusing garage door symptom sorts itself out with a balance test. Close the door first, because a door released while it is open can come down if the springs are already weak. Find the manual release cord, usually a handle on a short rope hanging from the trolley on the rail, and pull it to disconnect the door from the opener. Then lift the door by hand to about waist height and let go.
A healthy, balanced door stays roughly where you put it. It might drift an inch or two either way. If it slams to the floor or shoots to the top, the springs are not doing their job and the opener has quietly been making up the difference. If the door is so heavy you cannot lift it at all, stop and leave it down, because that is a broken spring rather than an opener fault.
The springs carry the weight of the door. The opener guides it along the track, holds it closed, and stops it when something is in the way. On a properly balanced door the motor is moving very little real weight, which is why openers look surprisingly small next to the doors they run. Understanding that division of labor is most of the diagnosis.
So the logic is simple. If the door is heavy by hand, the problem is on the door side, in the springs, cables, or balance, no matter how much noise the opener is making about it. If the door is light and easy by hand but the opener misbehaves, then it really is the opener, its sensors, or its settings, and that is a different and usually smaller job.
The door being hard or impossible to lift by hand. The opener straining, humming, or stalling partway up. The door dropping fast through the last foot of travel, or drifting down on its own after being left partly open. A visible gap in the torsion spring above the opening. A door that lifts crooked, binds in the track, or shudders on the way up.
These all describe a door that is no longer counterbalanced or no longer tracking straight, and not one of them is fixed by a new opener. Bolting a stronger motor onto an unbalanced door just moves the damage around: the new unit strains the same way the old one did, and the door keeps chewing through rollers and cables. Fix the balance and the opener complaint usually disappears with it.
The door closes partway and reverses. The opener runs but the door does not move. Nothing happens at all when you press the wall button. The remote works from three feet away but not from the driveway. The door will not close and the opener light blinks a pattern at you. Those are opener-side symptoms, and several of them have unglamorous, inexpensive causes.
The most common of all is the photo-eye safety sensors. Two small eyes sit near the floor on either side of the opening, and they must see each other for the door to close. A bike leaning in the path, a bumped bracket, a spider web, or a loose staple through the wire will stop the door and send it back up every single time. Check that both indicator lights are on and steady before assuming anything is broken.
Safe to check: whether the sensor lights are on and steady, whether anything is blocking the beam near the floor, whether the wall button works when the remote does not, whether the trolley was left disconnected after someone pulled the release cord, and whether the door feels light or heavy by hand with the opener disconnected. Those five answers cover most calls.
Not for you: springs, cables, and the drums they wind onto, and any door that is off its track, hanging crooked, or stuck in the open position. Leave the force and travel adjustments alone as well. They exist so the door reverses when it meets an obstruction, and turning them up to overcome a symptom defeats a safety feature. Call 801-823-6018 and describe what the balance test showed.
Look for a short rope with a handle, usually red, hanging from the trolley on the rail between the opener and the door. Pull it straight down with the door closed and the door disconnects from the opener. Reconnecting is usually a matter of running the opener until the trolley clicks back onto the carriage.
That points at the wall control or its wiring rather than the motor. The two send the same command by different paths, so when one works and the other does not, the fault is in the path that failed: a bad button, a pinched or stapled wire, or a loose terminal at the opener.
It is usually the other way around, since an unbalanced door is what destroys openers. But an opener with its safety reverse or travel limits set wrong can drive the door down too hard or too far, which stresses hinges, cables, and the bottom section. That is one reason the reverse test belongs in every service visit.
A few details about the door, or call 801-823-6018 if a car is trapped inside.