Garage Door Opener

check the travel, it may set too much.

check safety obstruction lights mounted close to bottom of door.
The most likely reason is that your lower travel limit needs adjusting. Your door may have settled or shifted due to age and weather changes and now contacts the floor before the lower limit switch is triggered. The opener sees that as the door not being able to close completely and, since that could be caused by something or someone trapped under the door, it reversed the door back to the open position as a safety precaution.

If the door only does this with the remote and you need to hold the wall switch button continuously to bring the door down then there could be a problem with the safety sensors near the bottom of the garage door itself. Again, the opener would see a problem there as a potential safety concern and re-open the door. Typically, however, a safety sensor issue will cause the remotes not to work at all and will reverse the door long before it reaches the floor. And any problem with the safety sensors should also trigger flashing of the overhead light.

Your owner's manual and the links below have more information that should help locate and resolve the issue.

This will happen if the IR sensor are sensing an obstruction while the door is closing OR if the IR sensors are defective. As a first option, check to see if any object is stuck to the door (possibly low down) that is triggering the IR sensor.
Hope this is helpful, if it was please click the 'Helpful' button below. Good luck

It sounds like a problem with the infrared safety beams, either they are not working, are misaligned (someone might have kicked/bumped into one), or I even had one that didn't work because there was too many cobwebs/dust covering one of the lenses.

Sounds like you have an RPM sensor problem.

There are a couple easy solutions for this. You can try switching the sensors side to side or use the cardboard tube that comes inside toilet tissue to shade the lens.

Terminal #1 - White wire with red tracer from wall control

Terminal #2 - Three solid white wires. One from wall control and one from each of the door sensors.

Terminal #3 - Two white wires with black tracer from the door sensors.

The motor is probably either stalling because the door is too stiff, or you have a beam break detector that is being triggered when the door is halfway down.

#2 and 3 on my opener. #1 and 2 are atteched to the wall button. So # 2 has both attached. Hope that helps.

Using the wall pad and holding it down bypasses the door sensors. The door should still open, make sure that there is power to the unit and make sure that your sensors are lit (Orange/Green) and pointed correctly. If all else fails, unplug the unit and leave it unplugged for at least an hour.