DIAGNOSIS: This is almost always a binding door, not an opener fault. The strain triggers the internal overload protector, which pauses operation.
FIX: Disconnect the opener by pulling the red emergency release cord. Manually operate the door. It should move smoothly throughout its entire travel with one hand. If it's stiff, lubricate all roller stems, hinges, and the track with silicone spray. Check for dents in the track or loose track brackets.
IF THAT DIDN'T WORK: The torsion springs above the door may be broken. Look for a gap in the spring coil. Do not attempt to repair springs yourself. This is a high-danger task requiring a professional garage door technician.
HEADS UP: Running the opener against a binding door will cause the gear failure mentioned earlier. Fix the door mechanics first, then the opener will work correctly.