The sensors can be misaligned just enough sometimes to cause this problem. The lights will be lit but if you look real close you can see them blinking every so slightly. Try tweaking them just a bit and try. You might try increasing the 'down force' a tad. This control is on the rear of the unit near all those white wires. Don't over do it as this affects the safety reverse.

If adjusting the safety sensors does not work, check the wire connections to the sensors. You might also try cleaning the sensors. If I spider puts a web in there it could interefere with the sensors.If you have had a power surge or lighting near by the senors may have gone bad.

But if it is a sensor problem wouldn't the door go back up at anytime I release the override wall controller? Once it gets started it goes all the way down.

Did you try increasing the down force? If it is a door sensor problem the main lights will blink 10 times. If it isn't doing this it isn't a door sensor problem. Sometimes if the down force is set too low the RPM sensor will reverse the door to the open position. The RPM sensor is what detects when the door hits an obstacle.

My garage door suddenly stopped closing this morning too. It will open with the remote and the wall button but will not close with either, even when I hold down the wall button. There are no lights on the sensors. When I hold the wall button down, I hear clicking in the main unit, but nothing else. Is it the sensors or something else?

This confuses me. If you can't get it to close how do you get it to open? Is your door stuck in the open position now? Look at the rear of the motor unit and see if the small LED is sending a code signal. It will flash a number of times and then pause. It will continue to do this. Let me know what the code is.

Just a follow up to my original issue. I traded out the sensor wires (thought there might have been a short somewhere) and then I noticed the chain looked a little loose. I tightened the chain and now it is working correctly. I hope this might help someone else with similar issues.

This all seems so helpful. Mine wont do down, unless I hold it from the main control. However, it does up with the remote. Hmmm? I'm gonna see if my sensors are covered with spider webs. It did start after sweeping. I hope it's nothing major.

when the door wont go down, almost always the two light sensors arent hitting each other, indicating to the garage opener that something is blocking the signal. Just realign the two sensors so that they are hitting each other, and 99% of the time the door will go back down with no problems

My door will only go down a couple feet and stops and reverses with no dome light flashing. The LED in back of the control unit is flashing a signal of 5 blinks. Don't have a manual for these signals. I'm using a Craftsman 1/2 hp closer With the Limit Switch Assembly. Floor sensors seem to be working correctly.