Question about Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+

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Door reverses about 1 foot from floor.

Both sensors are showing green lights. how can I override, or test the sensors?

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  • taylour Feb 09, 2009

    My garage door is reversing about a foot from the floor and I can't get it to open.



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You can overridride by pushing and hold wall button. If the door goes down and reverses up about a foot from the floor it could be a force setting issue on the opener or an issue with the door. First, pull the handle on the opener and operate the door manually a few times to make sure it opens and closes freely. You should be able to open and close the door with one hand or there is a problem with the door. If you determine that the door is ok then look at the force setting knobs. They are located on the back and have numbers from 1-10. These should be set on about 4-5 for the upforce and the downforce. I hope this helps.

Posted on Feb 07, 2009


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1 Answer

Garage door gos down and hits the floor and reverses back up. There is also a green light on one sensor and a yellow light on the other sensor. What would be the problem.

I know sometimes if the sun is shining towardso the sensor it will start to go up before hitting the floor but this soundshould like you may have a misaligned sensor or one of them going out but this doesn't explain why it hits the floor first so my answer to you is that the travel distance setting on the motor is not set right it thinks it's hitting something besides the floor the settings for the door travel distance should be on the back of the box that contains the motor I'm sure this is what is causing your problems

Sep 28, 2016 | Chamberlain Powerdrive PD422D 1/2 HP...

1 Answer

I have a Sears garage door opener model # 139.53985DM that reverses as soon as it reaches the floor, I have checked everything but I noticed on my sensors, one is green and the other light is yellow. Is...

The sensors are okay. It sounds like your door may be traveling too far in the down direction, hitting the floor and reversing. If this is so you can adjust the 'down limit' control located on the side of the motor unit. Turn this control just a tad in the opposite direction of the arrow printed on the cover. Some tweaking may be necessary to get it just right.

Sep 26, 2011 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

I have Sears Craftman 1/2 HP garage door open that want stay shut when you push the remote the sensor wire broke fix that. Now the door goes down and come back up. All sensor are led light are green...

Check the sensors again. Our unit has one amber and one green when working and if something (even a weed) breaks the optical beam it reverses and the lights blink. We've also had bright sunlight interrupt the beam. (The test for this issue is to stand such that you cast a shadow onto the sensor without being in the beam and then attempt to close the door with the remote). Next check if the door is binding during travel. If it is, check the tracks for plumb with a level and make sure the door rollers and tracks are undamaged. If a rail is crimped anywhere, it could be cause the problem. You can find some garage door sales places that sell the track sections and rollers to replace damaged parts. Check your local phone book and call around. In some cases, the door jamb may be damaged (lowering the header and shrinking the entire door area). This may require calling a professional to fix.

If the door itself is moving easily, then it sounds like the door might be hitting the floor too lightly or trying to go past the floor and triggering a safety reverse. On most of the openers, there are several adjustments you can work on to reset this. First try adjusting the down limit to above the floor and then bring it back to the floor. (However, usually these do not make the opener light blink.)

Alternatively, adjust the downward force to a higher value.

Without knowing the model of your Craftsman opener, I'll just use the directions for mine. All of these are adjusted with a flat blade screwdriver. Always test each adjustment with a complete up and down cycle.

The height limit control is on the side. (It's the forward one of two screws inside the cover - you should be able to reach them thtrough holes in the cover. Unfortunately, sometimes it's easier to get to them after removing the cover. The cover is held by 4 screws - 2 on each side.) To decrease the travel, turn the Down screw clockwise. One full turn of the screw is 2" of door travel.

The force controls are on the back with the down adjustment on the right. Turn this clockwise in 10 degree increments and test each time.

It is possible to overheat the opener with too many open and close cycles. In that case stop adjusting the unit and wait 15 minutes for it to cool.

I hope this helps.

Cindy Wells

Nov 27, 2010 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

When the door is open and you go to close it , it travels about a foot then reverses and motor unit flashes. what could be wrong, I checked the sensors and they are showing green.

Any time the main light flashes 10 times and the door reverses to the open position it is a door sensor problem. Check them closely. If one of them is flickering ever so slightly it will cause this problem. Also make sure they are fastened securely so that they are not moving when the door closes.

Nov 22, 2010 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Have a Craftsman 1/2hp garage door opener (HBW0777 year 1994). It won't close and goes back while blinking 8 or 9 times. Transmitting sensor (red light) is blinking 3 times (even i hold the two sensor...

Anytime the main light flashes 10 times and the door reverses to the open position it is a door sensor problem. If the transmitting sensor light is blinking it is bad.

Nov 20, 2010 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Liftmaster 1/2 horse Model HBW0777 acts like the safety sensor is stuck (door won't continue down - re-opens when you let go of the wall button. I can close it with the wall button but I need to hold it...

If the main light flashes 10 times when the door reverses it is a door sensor problem. Look closely at the green lights to make sure one isn't flickering ever so slightly. Tweak them a bit.

Mar 22, 2010 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

No matter where the door is located on the track when i engage it to the pully and press the button it will go down about 1 a foot and then stops and comes back up about 1 a foot and the lights blink....

There is an adjustment for how much 'torque' the unit is using to lower the door, and if your door is jamming or if this setting is set too low, the door will reverse. There are 4 adjustments on this unit: one for all the way up, one for all the way down, and the one for 'jams'
First: make sure you have BOTH a yellow light on one sensor and a green light on the other sensor. 2nd: Go inside the gararge (keep kids and pets away) and press and HOLD down the close/open button and keep holding it - this is an override for the photoeyes and your door should go all the way down to the close position. IF if doesn't, then you need to adjust the white knob that will allow it to close. It is testing to see if you have a jam, and the setting might be too low, or your door is binding. If these don't help, you'll have to call a pro. Good luck my friend.

Aug 21, 2009 | Kitchen Appliances - Others

1 Answer

Left Sensor has yellow led & right sensor is green. Garage closes and then immediately opens. I'm assuming it's the sensor with the yellow led. How do I fix this?

If the main light flashes 10 times when the door reverses it is a sensor problem. Make sure the door isn't hitting the floor and then reversing. This problem will not cause the light to flash 10 times and can be corrected by adjusting the 'down limit' which is on the side of the motor unit.

Jul 30, 2009 | Sears Craftsman LiftMaster Chamberlain...

2 Answers

Door hit bottom and goes back up. one sensor light is green and

your door must have a pressure switch, and it is hitting the floor before the motor stops.

with the door topped out, release the lock and push the door closer to the motor and relock.

have a helper present to be safe

Jul 03, 2009 | Sears Craftsman LiftMaster Chamberlain...

2 Answers

Garage Door Wont Close Craftsman 1/2 HP (1998)

What it is is the electric beams at the door are getting blinded buy the sun or out of line. They are the two black boxes on both sides of the door about a foot from the ground. Put a piece of card board in front of them not blocking the beam dut to block the sun. All that they are is safety beams for kids so they do not get hurt. If you have to move them to the top where the sun will not hit them. Sorry to say though you can not remove them all the way. Also make sure the lite on them is not blinking if so they are out of line.

Good Luck and Please Rate FixYa!

Mar 03, 2009 | Sears Craftsman LiftMaster Chamberlain...

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