Garage Door Won't Close - How To Adjust Liftmaster Safety Eye Sensors

In this video we troubleshoot misaligned garage door safety sensors, describe how the Liftmaster safety sensor system works, explain how to adjust the safety sensors properly and offer some tips on how to prevent future garage door safety sensor related issues.

[@mariannechmeleck7423]

Thanks so much. I looked at 3 videos and found that my sensors were working properly. But yours was the only video that offered a solution for a door that comes down and goes back up. You said the door might be bent…and i checked the insulation panels i installed and 2 of them were coming our of the slots. Voila!! Fixed and working perfectly!

[@firstclassgaragedoor6471]

Great! Glad it was helpful. Thanks for watching.

[@yevgeniymaksimovich8505]

Real good explanation about safety sensors purposes and adjustments. As garage door technician I like your approach. Most videos on KZbin just confuse my customers even further!

[@firstclassgaragedoor6471]

Kind of what led to the making of this video. Thanks for watching and the feedback !!

[@drtrotter21]

My door would only close if I held the button down, otherwise it would go back up again. Can't believe I lived with that problem for a month until watching this video. Took me all of 60 seconds to diagnose and fix the problem. THANK YOU SO MUCH!

[@firstclassgaragedoor6471]

You’re welcome. Thanks for watching, I’m glad it was helpful.

[@suryamamidi8607]

@drtrotter21 I am having similar issue? How did you fix the issue? Both sensors showing solid orange and green lights

[@ntkt5869]

Very informative with lots of extra scenarios to help troubleshoot. Love it. Thank you!

[@firstclassgaragedoor6471]

Thanks for watching!

[@johnydip1510]

Tks for the clear explanation! I had kicked my sensor off and needed to fix it, like you said it wasn’t square and caused the light to flicker. great job on the video!

[@firstclassgaragedoor6471]

Thank you and thanks for watching! Glad you were able to fix it.

[@cat2112cat2112]

Very helpful video. We fixed the alignment of one sensor in 10 seconds and now the door operates correctly.

[@firstclassgaragedoor6471]

Thank you for watching. Glad it was helpful.

[@richardtracy2627]

Most helpful video i have come across on this issue.Solved my issue i was having.Thank you sir.

[@firstclassgaragedoor6471]

You are Welcome and Thank you!

[@RG-rx5wz]

SOOOOO happy to find your video......very helpful....especially the part about looking closely at the green light.....mine appeared to be lit until I looked closely! Thank you very much

[@firstclassgaragedoor6471]

Thanks for watching, Your welcome!

[@gregorywilliams6553]

Very helpful video. This solved the problem and I learned something in the process. Thank you. Just saved me a lot of money from having to call a garage door repairman.

[@firstclassgaragedoor6471]

Glad it was helpful. Thank you for watching.

[@maggiearazi]

Thanks so much. This was exactly the problem with my garage door! The step by step explanation was so helpful, like which is the sending vs receiving eye, that the lights should be solid not blinking! Really appreciate your calm detailed video!

[@firstclassgaragedoor6471]

Thank you for watching! Glad it was helpful.

[@alohaxmel]

Thanksssss so much for your video! I fixed my sensor’s finally thanks to you!!!

[@firstclassgaragedoor6471]

Glad it helped!

[@natashamckenzie4878]

Thanks so much , exactly what I needed to fix the garage door

[@ktmxcw4501]

Hey man thanks for sharing the knowledge. I was fighting the alignment on my door that was reversing about 5 inches from being all the way closed. You gave every possibility and i found a single leaf hanging from the door about a foot from the bottom. When the door went vertical, it went right in the path of the sensor. Thanks again!

[@firstclassgaragedoor6471]

No problem. Thanks for watching,

[@danield1673]

Thanks for this. This could very well be my problem too(see comment above). I will check tomorrow. Was the leaf on the bottom of the door where the rubber portion is and traveling up and down with the door?

[@user-nb1qi7fn8m]

Thanks for the video , it helped me adjust my sensors.

[@waltb4415]

Solution: Lousy connections between the sensors and the long wires leading back to the motor were the cause. The installer gave the raw wires a twist, then wrapped in electrical tape, which degraded over the years. I soldered the wires and that was a solid fix. Tip: a solid green receiver LED is necessary, but insufficient for reliable closing. Solid connections are necessary as well. New sensors come with pinch-connectors, filled with dielectric paste. Original Post: My green sensor is continually green, no flickering. The opener flashes a 4-6 code, indicating sensor misalignment. The sun is not shining on the sensors. The sensors are 6 inches above the ground, clipped to the tracks like yours. I loosened the wing nuts, then aimed them and re-tightened. The green sensor is in the middle of it's band, i.e. I can point up a ways and down a ways before the green LED goes off. The Liftmaster 7675 is a "Q" type with a yellow Learn button. It has worked since I bought the house in 2016. There are many online instructions for handling a 4-6 code. All of them say "Align your sensors until the green light is solid". I have done that. What could cause a 4-6 error code with a solid green reversing sensor LED?

[@firstclassgaragedoor6471]

Yeah, scotch loc connectors or solder and heat shrink. The codes are general, check alignment is a 99% of the time fix and for consumers typically as far as their knowledge will get them but yes, technically it could also mean a compromised wire(s), connection(s) or termination(s). Glad you were able to trouble shoot and repair.

[@timmelany3291]

thanks your video helped me take care of that problem, I bumped my sensor accidently and i took it out of alignment.

[@firstclassgaragedoor6471]

Thanks for watching. I'm glad it was helpful.

[@marymullins5620]

This helped me so much! My garage door is now working. Thank you 😊

[@firstclassgaragedoor6471]

Great! Thanks for watching!!

[@TheInnerRealms]

Thank you!! I must have knocked the sensor when taking my kayak out. Love the DIY fix!!

[@firstclassgaragedoor6471]

Glad it was helpful.

[@elizabethhammond8073]

Solved my problem! Thanks. It was cobwebs!

[@firstclassgaragedoor6471]

Great! Thanks for watching.

[@brucepalmer4396]

Your garage floor looks good.

[@firstclassgaragedoor6471]

Thank you!

[@bobnik0484]

Thanks. I guess I bumped the sensor. Got it working. Appreciate your help.

[@joelwest1049]

😊 thanks for all your help I followed your video

[@user-gy6lk9pq7h]

Greetings- Very informative and clear video! Unfortunately , none of these worked for me on my Liftmaster. Lights on and aligned. Lenses cleaned. Unpluged and re-pluged the main unit. I am stumped. Remote still opens, but won't close the door. Would it make sense try replacing the remote controller? We rent, so I hesitate to solder the connections myself. Thanks & much respect, -Kimbo

[@firstclassgaragedoor6471]

Thank you. Well, if the remote opens the door it would be odd that it wouldn’t close it. Assuming all the basics are in fact good I would say you have a bad set of eyes or a bad logic board on the operator. Might be time to get a professional over as they would be able to trouble shoot a bit easier. Or, if you want to order a set of new eyes and hook them up direct to the opener, if it works great, if not you may be stuck with the sensor cost and still have a problem.

[@rbjac6066]

Thanks - clear explanation

[@opticyclic]

What are you supposed to do if it is completely out? e.g. the wing nut came off. Do you just keep wiggling in all directions and guessing?

[@felixdejesus9038]

Thank you for the information! it fixed my problem 🎉🎊

[@firstclassgaragedoor6471]

Thanks for watching, glad it was helpful.

[@user-mv1wg3wt7l]

Easy fix, thank you!!!

[@firstclassgaragedoor6471]

Thanks for watching!!

[@robi7017]

Great video. Thanks for posting.

[@firstclassgaragedoor6471]

Thank you!

[@jeffhoffman8001]

Thanks for the video! Exactly what happened to one of my safety sensors...realigned sensor and issue has been resolved in just a few mins...Thanks again

[@firstclassgaragedoor6471]

No problem. Thanks for watching, glad it was helpful.

[@Silverstatetrains]

Very helpful. Solved my problem.

[@firstclassgaragedoor6471]

Great, Thanks for watching!

[@kip7064]

Thank you

[@firstclassgaragedoor6471]

You are welcome. Thanks for watching!

[@renragged]

The one at our shop works perfectly until the sun is in just the right place during the morning. It's 10:00 am today and I keep getting the 4-6 error. When the sun moves it will work correctly. Is there some way to prevent the bright sunlight from causing this issue? I've parked my car in front of the garage to create a shadow but it still won't work. So frustrating! I'm trying to leave to get to a customer but I can't because the garage won't close. UGH!

[@firstclassgaragedoor6471]

The safety sensors work with infrared light. The beam or laser that goes across the opening is actual IR light. The sun emits infrared light. This can interfere with the safety sensors. If you are blocking the sunlight and the door still won’t close I would guess that the sun is not the problem. Could be an alignment issue, dirty sensor lens, bad eye(s), wiring or a bad logic board. Good luck.

[@josemoreno3334]

Thanks.

[@firstclassgaragedoor6471]

No Problem, Thank you for watching !

[@JoJo-wk4cx]

Thank you. I fixed my problem!!

[@firstclassgaragedoor6471]

No problem, Glad you were able to resolve your issue.

[@aperson1181]

so my sensors are okay, but suddenly, the craftsman garage door opener stopped operating, and the yellow led is slowly blinking, why suggestions? It seems like the control unit that is attached to the wall is not responding, for some reason. Only lights get turned on when you cross the sensor path.

[@reikisponge]

thanks for the video. it's very helpful. nice garage floor. what product do you use and whether it gets hot tire pickup marks over time?

[@firstclassgaragedoor6471]

Thanks for watching, glad it was helpful. I used Floorguards H2O HyperPrime, Hyper Flex 100% solids epoxy, Full broadcast and their Aspartic 85 Polyaspartic top coat. Didn't scrape the flakes just picked up the loose ones so it took a lot of the aspartic to cover. I didn't want the textured surface as my kids use the garage as a play area most of the year and the texture catches dirt when moping/washing the floor (juice spills and ground up gold fish crackers as well as their muddy shoe tracks) so I wanted the poly to completely cover the flake. Used poly beads for traction, was told to mix them in with the aspartic but IMO they work better when broadcast over the aspartic after application. No issues with tires, just re did the entire exterior of the house and used the garage as a work area, dropped several framing hammers, big prybars and other tools on the floor on multiple occasions, no damage. Also left a roll of Winterguard ice and water shield (from the roof replacement) on the floor, it got stuck to it and left some tar stuck to the floor, have yet to try getting it off, I'm sure it will come off but curious to see if the solvent/brake parts cleaner will cause any damage or clouding to the polyaspartic top coat. I know my father in law has the Home Depot Rustoleum epoxy floor coating with flake and the tires are pulling the coating off but you cant compare a $200.00 or $300.00 floor coating product to a $3,000.00+ floor coating system (material cost only - ~450-500sqft). Although even a professional coating system and/or professionally installed system coating can come up if its not installed properly and/or if there is moisture under the concrete. Maybe TMI but may be useful to someone else down the road.

[@reikisponge]

@@firstclassgaragedoor6471 Thanks for the details. I appreciate that. Yes I did use the Rust-Oleum product and the hot tire pickup was an eye sore. I eventually bought the parking mat to cover up the ugliness and it also helps me park and stop exactly without being hit by garage door or leaving too little space in the front that we can't walk through.

[@timhieuiaocvaoisonghoaky1749]

Good clip, thanks

[@ChrisGillard-ll3nk]

Awesome info thanks

[@firstclassgaragedoor6471]

Thanks for watching.

[@AntLive29]

Thanks. Amazing floor BTW. is that epoxy?

[@firstclassgaragedoor6471]

Thanks. Yes, epoxy with aspartic top coat. Thanks for watching.

[@bobanderson577]

Thank you!

[@mikebelfield76]

Very good!

[@Ptran1819]

My sensor had yellow light. I did clean eye and adjust alignment but still have yellow light. May you please advice what can I do? I bought my house since 2007 liftmaster brand name. If I replace new one it didn’t have that part the same liftmaster sensor I have know. Thanks a lot

[@firstclassgaragedoor6471]

On the newer Liftmaster sensors there will be a yellow/amber light (always on) and the other a green light (only on when sensors are aligned and unobstructed). If your still having trouble it may be time to have a professional out. Thanks for watching and good luck.

[@Ptran1819]

@@firstclassgaragedoor6471 when I closed garage door it reserved back. What else reason do you think? Thanks a lot.

[@judydevonish3067]

My garage closes and open by itself. Is there anyway I can lock it . I have a craftsman motor and Chamberlain remote

[@firstclassgaragedoor6471]

Get it closed and unplug the power cord. That’s the only way to ensure it won’t open on its own. If you know it’s a remote causing it to open and close you can turn on the Lock feature assuming your unit is equipped (press and hold the “lock” button for a couple seconds to turn on or off) if it’s not being caused by a remote this will not stop it from happening.

[@marttileivo5151]

I have a Chamberland Lift master that has worked flawlessly. I closed the door with my remote and opened it, but then I couldn't get it to close. I hear the motor making a sound for 2-3 seconds and that's it. I checked sensors, and tracks and so far everything seems to be correct. Any suggestions would be appreciated, thanks.

[@firstclassgaragedoor6471]

Did you check the emergency release ? If that is engaged properly it may be a stripped gear or the sprocket could have broken off, either are common problems with Chamberlain chain drive units. Hope that is helpful.

[@marttileivo5151]

@@firstclassgaragedoor6471 My unit is not a chain drive

[@danield1673]

My app told me it was a sensor issue. For me it is sporadically. Like it will be fine one time and then the next time it will reverse a few seconds after it descends. One time it also reversed 1 foot prior to hitting the floor, but not recently. I checked the sensors and the alignments and everything looks good/steady lights. I did brush away any debris or cobwebs near sensors and underneath the door. Any ideas or things to look out for? TY

[@firstclassgaragedoor6471]

If you can’t wiggle the sensors without the led light going off or flickering the sensors aren’t lined up properly and if they aren’t lined up properly the door may reverse at any number of positions. The sensors are likely clipped on to the door track, when your 150-500lb door moves it may vibrate or shake the track which could cause the sensor to go out of alignment. Hence the importance of having the sensors installed and adjusted properly. If your certain everything is as it should be and still have issues it could be a wiring issue, a bad sensor or a bad logic board.

[@user-xk8dx6we1k]

Wow what you said first was happening. I was wiggling the green sensor to fix alignment and I noticed if if I went to far up or down it was still staying a constant green and not flickering or going off. So does this mean I need to play with sending. What do I need to do in this scenario?

[@user-xk8dx6we1k]

Or is that solid green (no matter how it wiggles up or down good) since it means it's receiving the sending?

[@firstclassgaragedoor6471]

@@user-xk8dx6we1kyou should be able to wiggle either sensor up and down as well as in and out (toward and away from the door opening) to some degree without the green light flickering. This is all covered in the video. I’m happy to provide some advanced trouble shooting but it sounds like you need to watch the video a couple more times to get the basics dialed in first, if your still having trouble it might be time to call a company out. Thanks for watching and good luck.

[@danield1673]

@@firstclassgaragedoor6471 Yea that's what its doing. I am able to wiggle all around and it still stays steady green so I think thats good since its synced with the amber signal. I removed a few leaves from the bottom of the rubber and its working okay now. I will monitor. Fingers crossed. Thanks for your help.

[@derekkchung]

2 wires going to the receiving eye. What are they for? 12V power and ground? I would imagine it needs a third wire for signal? I got a SOLID green LED while the door is closing but it would still stop and bounce back and then 10 flashes.

[@firstclassgaragedoor6471]

Liftmaster does not give specs to do tests on the eyes or any part of the system for that matter. Yes, typically you would have power, ground and a signal. Not that simple though, they are running power, ground and signal over two wires. I don’t know how they do it, that would be a question for an electrical engineer. As for the problem, starting with the easiest - re splice any and all connections, if that doesn’t do it, replace eyes, if not that replace board. If unit is 15yrs old or more, replacing the unit may be the way to go.

[@derekkchung]

@@firstclassgaragedoor6471 Right, I am looking at my problem from an engineering point of view, wondering why 10 clicks when both LEDs are on solidly. My sensors are pre-99 which might have different scheme than the amber and green version most people have. I will just change them so that I can fix it all in one shot. BTW, here is a good video for those who wants to know the answer to my question. See video = GbmufXgpl14. THANKS FOR THIS VIDEO. IT IS ALSO VERY HELPFUL, HELPING ME TO DIG DEEPER.

[@firstclassgaragedoor6471]

@@derekkchung Wish I had an answer. I have seen no LED's on the eyes and they function perfectly fine, as well as LEDs on and never go off but eyes still work okay. Best advice I can give is to use weathertight connectors and/or die-electric grease on any connections and make sure all connections/terminations are good, high resistance will cause problems. Thanks for watching and sharing!

[@derekkchung]

@@firstclassgaragedoor6471 Right. It is more than just a ground or positive voltage signal, or a certain resistance. There is circuitry inside that gives pull-to-ground pulses every few msec that the mainboard is reading, making it impossible to troubleshoot or eliminate / bypass the sensors. Maybe my sensor fails to send that pulse signal. I sure will use di-electric grease when I redo the sensors when they come. Thanks.

[@lerhroyquerol6959]

Can’t see small lights on sensor lift master.

[@Kion1972]

ok so I've cleaned dust/dirt, from sensors and they are aligned, and it still only opens a little, then closes. On the actual thing on the ceiling, it flashes 4 times up, and 2 times down. Whats your thoughts?

[@firstclassgaragedoor6471]

Sounds like a broken spring. Safety sensors only function on the close cycle. No one is particularly worried about opening the door on someone, just closing on someone and crushing them between the door and the floor. Have you tried operating your door manually? You should be able to lift it with one hand, two fingers really.

[@Kion1972]

yep! its the spring. thx

[@anthonyortiz7264]

I can’t figure out how to align my sensors.

[@timwatring2454]

So if both sensors are solid green and not flickering but the door still won’t go down and blinks as if there is a obstruction…

[@firstclassgaragedoor6471]

Check connections and terminations. If still persists the cheaper option is to swap the eyes, if there is still a problem and you are positive its not in the eyes, connections, terminations or wire itself then its likely the board on the motor unit. If this is a residential unit with two green LED's, its probably pretty old (15+ yrs) and I would just replace the whole machine. Hope that is helpful.

[@sharonsopczynski1192]

So my door won't close for years left side has always been red the other is green and always worked so why would it stop now

[@firstclassgaragedoor6471]

Just because the door won’t close does not necessarily mean it is a photo eye issue. Without any additional info regarding make, model or specific symptoms it’s impossible to say what the issue is. As for the unit working for years and now all of a sudden not working properly, thats just how a problem works. One moment everything is fine and the next it’s not. Easiest way to diagnose or rule out the phot eyes would be to install a new set of eyes, if it works then that’s the problem. If not, then the operator itself and internal components would need to be looked into. I’m assuming the door is in good working order. I have seen photo eyes that appear to be working fine visually but they are in fact bad.

[@2232smiles]

What if both lights are off? How or which one I need to fix first?

[@firstclassgaragedoor6471]

There is a sender eye and a receiver eye. The receiver eye cant receive the "signal" if the sender is not sending therefore the receiver eye sensor light would not come on so you would need to determine if the sender eye is bad, the wire is bad or the opener board is bad. The sender eye light should be on all the time. To eliminate a possible bad wire you can cut the photo eye wires 8-12" back from the eye sensors and wire them right up to the back of the opener. If it works like that there is either a bad/broken wire or bad connection between the operator and the eye(s). If they still don't work it could be a board or the sensors themselves. From here the cheapest route would be to get a new set of eyes and connect them the same way (right to the board, prior to installing the new eyes and running the wires) If the new eyes work your good if not its likely a bad board on the opener. Do NOT cut the photo eye wires with the opener plugged in, do NOT connect the safety sensors with the opener plugged in. Whether its just coincidence or not I have had more eyes go bad by connecting the eyes and/or cutting the wires (both at once - White and white & Black wires) with the unit powered up. Either way make sure the unit is powered down when wiring the eyes or wiring them. That includes disconnecting the battery in units with backup systems. Hope that makes sense.

[@2232smiles]

@@firstclassgaragedoor6471 thank you but I found the problem, it was one of the connections that goes to the sensor on the motor it was loose so I fix it now it works thank you

[@1sideslip]

Are the Orange and Green lights on all the time???????????????

[@firstclassgaragedoor6471]

They are supposed to be. Assuming the eyes are lined up and everything is working properly.

[@1sideslip]

I have a older Chamblin system, and the lights are not on all the time. This new system , I thought the Green light was the one that was the problem because it was flashing all the time. I found out it was the Orange light that was the problem, because it was loose in the holder. When I tightened it .THe green light came on steady and .,after I ran the door up and down a couple of times the lights go out. I waiter a while, and ran the system again and left the door opened for an hour allthat time the lights stayed on. But when I closed the door the lights go out. The system works find now.

[@theinfinityshield]

The issue is these garage door sensors are so outdated in their technology. Take a look at a sensor that can solve the sun issue, alignment issue, coverage issue and also help guide your car in the garage! Let me know if you want to give this a try?

[@harperfollansbee7276]

👍

[@2232smiles]

What is none of the light are on? I need to buy new sensors?

[@firstclassgaragedoor6471]

There is a sender eye and a receiver eye. The receiver eye cant receive the "signal" if the sender is not sending therefore the receiver eye sensor light would not come on so you would need to determine if the sender eye is bad, the wire is bad or the opener board is bad. The sender eye light should be on all the time. To eliminate a possible bad wire you can cut the photo eye wires 8-12" back from the eye sensors and wire them right up to the back of the opener. If it works like that there is either a bad/broken wire or bad connection between the operator and the eye(s). If they still don't work it could be a board or the sensors themselves. From here the cheapest route would be to get a new set of eyes and connect them the same way (right to the board, prior to installing the new eyes and running the wires) If the new eyes work your good if not its likely a bad board on the opener. Do NOT cut the photo eye wires with the opener plugged in, do NOT connect the safety sensors with the opener plugged in. Whether its just coincidence or not I have had more eyes go bad by connecting the eyes and/or cutting the wires (both at once - White and white & Black wires) with the unit powered up. Either way make sure the unit is powered down when wiring the eyes or wiring them. That includes disconnecting the battery in units with backup systems. Hope that makes sense.

[@maninscrubdallas8694]

What if the door wouldn’t open and the orange light is off?

[@firstclassgaragedoor6471]

Check for power at outlet, if good check accessories (safety eyes and wall control) for indication of power, assuming the motor is not overheated and there is power to the outlet for the opener, if you have no power to accessories I would try replacing the board.