TECHNICAL REFERENCES: Troubleshooting Photo-Eyes

If photo-eyes are the suspected source of the problem, there is an easy way to troubleshoot the issue.

Follow the link.



  1. Keith Sutton's picture
    Mar 25, 2024

    Neither photo light comes on...door opened this morning; but, will not function now. Have disconnected the seems to be working properly. We had a power flux last night; which may have caused the problem. What do you think??? Thanks.

  1. Brian's picture
    Mar 25, 2024

    Power surges tend to target the logic board and lightning strikes the photo-eyes.  Does your garage door opener work when constant pressure is placed on the push button (photo-eye over-ride).  If yes, replace the eyes.  If no, repace the logic board.

  1. Craig's picture
    Feb 23, 2024

    I purchased a Model 615 opener and had it installed through a local garage door company. A few months after installation it started having false-positives of an object in the door path and would not go down. The green light was flashing. I called the installer, and he came out and was able to get the emitter and detector aligned. Recently the problem has occurred again. A flashing green light on the emitter. Once again I am not able to get this aligned. In addition the door does not stop and go back up at the same point. Sometimes is is 3/4 down, other times 1/2 down, and sometimes a 1/4 down. Just recently it has begun stopping just after it starts. There is no rhyme or reason to when it will stop and go back up. Is there a way to test the emitter, receiver, and any circuit board on the system? This seems more like a hardware/firmware issue to me at this point.

  1. Brian's picture
    Mar 17, 2024

    Photo eye alignment is sometimes a little tricky.  Alsp, it appears that the limits may not have been set properly.  Call Guardian tech service 424-272-6998 for help.

  1. Laurence's picture
    Jul 30, 2022

    Greetings, I'm hoping you can help me with a few questions/issues:

    I opened my garage door, and when I went to close it, it beeped repeatedly. I checked the sensors, one is green, one is yellow. I tried cleaning the sensors, adjusting, eat to no avail. Weird thing, one was green, the other yellow, then after trying to re-align, I noticed the other was now green, and the other is yellow. Help?

    Second, as I live in AZ, we had a monsoon storm roll in so I had to close my door. I used the emergency release and closed the door. Now the trolly is stuck in the "door up" position and I can't re-engage the trolly.

    This may be due to the fact I tried to adjust the travel limits (it beeped 5 times when I hit the door button) The up worked just fine (without the door bad!) but when I try to adjust the travel limit to down, again it beeps several times without any movement.

    I'm assuming I'll need to call support, but am hoping you might be able to help! Thank you in advance for your guidance!

  1. Brian's picture
    Jul 31, 2022


    Please call tech support at 424-272-6998.  The tech will help you sort out the issues.

  1. Richard's picture
    Jul 28, 2022

    The green photo eye blinks and is not solid. The red one is solid. I remember the green PE used to be solid. I can not align to make the green one solid. But everything else function correctly. Anything wrong?

  1. Brian's picture
    Jul 28, 2022


    It's best to call 424-272-6998 for troubleshooting help.  However, check the photo-eye wires at the power head.  Are there wires in all 4 of the marked terminals?  At times, installers make twisted pairs and only use 2 of the 4 terminals.  This reduces the power supplied to the eyes and could have a damaging effect over time.  It could be the souce of the intermittent flashing.

  1. Richard's picture
    Jul 28, 2022

    Yes, I can see only one pair PE wire in the opener terminals. Do I need to replace anything or can I fix it?

  1. Brian's picture
    Jul 29, 2022

    Try rewiring.  Unplug the opener.  Untwist the pairs.  Insert one wire into each of the 4 terminals.  White-black stripe-white-black stripe.  Plug-in the opener.  Full power will now be reaching the photo-eyes.  Check alignment.  If flashing green persists, permanent component damage may have occured and the photo-eyes will require replacement.

  1. Anonymous's picture
    Jul 29, 2022

    Problem fixed. There are only one pair of PE wire visisable. I changed to the other two terminals and align.. Thanks.

  1. Brian's picture
    Mar 10, 2021

    If the operator is working from the wired push button control and the hand held remote control, the issue is with the keypad.  

    When pressing any digit on the keypad, a backlight/illumination of the buttons should be seen.  If there is not a backlight, then the keypad does not have power.  Check for contact between the batteries and terminals or corrosion on the battery terminals. If contacts have been broken, the keypad will need to be replaced.  If there is corrosion, use a solvent or wire brush to remove.  

    If power has been verified, return to the programming process.  After pressing the LEARN button on the operator (30 second code learning mode entered) enter a 3-6 digit code (pressing each digit firmly and in the center of the key) and press the ENTER button on the keypad, 2-beeps should be heard from the operator to acknowledge learning the code.  If the 2 beeps are not heard on first press of the ENTER button, try pressing the ENTER button more firmly and in the center of the button one or two more times.  If this works, there has most likely been some wear or damage to the contacts under the ENTER button and the keypad will work intermittently.  If programming fails, remove the keypad from the door jamb and repeat the coding process closer to the operator head.  (If there is RF interference, possibly from an LED coachlight, programming the keypad closer to the motorhead may help).  If keypad keys are glowing and the code learning process fails while the keypad is closer to the operator powerhead there is most likely a short on the traces and keypad will need to be replaced.  

    Calling a Guardian Tech service rep at 424-272-6998 while troubleshooting may provide some additional insight.

  1. Anonymous's picture
    Mar 11, 2021

    Thanks. Changed the batteries to be safe, and confirmed their is illumination from behind the keys. Successfully performed the re-program, and it worked. Keypad is still not working. I will try to remove the keypad and look at the contacts. If needed, can I simply order a new keypad directly from you? I'd prefer not to go back to the installed (it's only been a year) as I don't have trust or confidence in them.

  1. Brian's picture
    Mar 11, 2021


    Please call 956-998-4011 x205 and ask for an RGA.  Return the kepad with any of the purchase documents that you have on hand in order to veryfy date of purchase or installation to our tech center and we'll take a look at it.  A repaired or new keypad will be returned.

  1. Anonymous's picture
    Mar 15, 2021

    Brian - I took the keypad apart and cleaned it, and it seems to be working fine now. I will retain the contact information should there be any issues down the road. Thanks!

  1. GZ's picture
    Mar 09, 2021

    Keypad is WKCC and Opener is 2211-D

  1. Brian's picture
    Mar 06, 2021


    What is the model number of your opener and model number of the keypad?

  1. GZ's picture
    Mar 04, 2021

    Door is fully operational but keypad doesn't work. Changed batteries. Even changed code after installing new batteries and still not working. Less than a year old. Thoughts?

  1. Brian's picture
    Sep 21, 2020

    Hi Stuart,

    Please call 424-272-6998 for troubleshooting help.

  1. Stuart's picture
    Sep 19, 2020

    I press the button and door goes 6 inches then returns. I have adjusted the force , I have checked the sensors , I have lubricated the system, and even if I hold the button down it still returns.

  1. Brian's picture
    Aug 24, 2020

    "Universal photo eyes" from HomeDepot will not work with a Guardian opener.  Guardian photo-eyes can be found on-line by seaching for GUAT-201 or GUDT-208.

  1. Brian's picture
    Aug 24, 2020

    Hi Terri,

    It's best to call 424-272-6998 for troubleshooting help.

  1. Terri Torres's picture
    Aug 19, 2020

    The motor beeps 12 times and the door will not shut. We followed the instructions for adjusting travel limits. When the down button is pushed after pushing the limit button twice, it only beeps and the door will not go down. The photo eyes are solid red and solid green and are not obstructed. What else can we do to fix this?

  1. Paul's picture
    Aug 18, 2020

    Can I go to home depot and get universal eyes?
    I have the 600 SL the book calls for GUDT-208

  1. Brian's picture
    Jul 27, 2020

    Hi James,

    It's best to call 424-272-6998 for troubleshooting help, but from what has been described, I supect a new circuit board is needed.

  1. James 's picture
    Jul 24, 2020

    Garage door went up the other day and when pressing the button for it to go down I now get the twelve beeps. I looked and noticed that both Photo Eye lights are out. I tried adjusting them both but I get no light on either. Please help.

  1. Brian's picture
    Jul 15, 2020

    The PE with the red LED is the receiver and will illuminate when continuity is detected.  The green LED PE is the sender.  The green light will illuminate solid with continuity or flash when there is power but no continuity (alignment).  If powered up and the LEDs do not  illuminate (as you have described) and the door can be closed by a constant press of the push button (press hand hold for ~5s to initiate), the circuit board is not bad., the problem is with the photo-eyes and they should be replaced.

  1. Josh's picture
    Jul 13, 2020

    Hello I followed the troubleshooting guide attached here and I cannot get either Photo Eye's LED to light up. I moved both to the unit and plugged them directly in as the troubleshooting guide says to and still nothing. I have a Guardian 600SL, and using a multi meter I am showing 21.3v DC coming from each terminal. Any assistance would be appreciated... I am assuming I just need to replace the photo eyes but it is weird that neither the green or the red LED will light up (pointed at each other or not). Thanks!!

  1. Brian's picture
    Jun 21, 2020

    Hi Harris,

    Yes, the GUAT-201 replacement photo-eyes are correct.

  1. Harris R's picture
    Jun 12, 2020

    Can I use the 201 photo eyes for model 628? My red eye is not lighting. Green eye is blinking. I am thinking its a broken red eye.

  1. Brian's picture
    May 03, 2020

    Hi Mike,

    It could be a stuck relay on the circuit board.  Please call 424-272-6998 for troubeshooting assistance.

  1. Mike's picture
    May 02, 2020

    The red and green lights are solid but when I attempt to close door it beeps repeatedly I tried holding down button but the same result no door movement

  1. Brian's picture
    Apr 03, 2020

    Hi Eric,

    Please call 424-272-6998 for troubeshooting assistance,

  1. Erick's picture
    Mar 30, 2020

    Door open, wall and remotes give a 5 chime error code. Double press on limit to change to down, then pressing down give a 12 chime error. No remotes work while continuing to hold.thank you

  1. Brian's picture
    Mar 14, 2020

    Hi Edward,

    1. Please be sure that all 4 wires for the photo-eyes have been inserted into separate terminals (in the terminal block in the motorhead).  Low current to the photo-eye causle be causing the green LED to flash.

    2. There may be a chance that PE circuitry was damaged by a power surge causing the green LED to flash.  (PE would need to be replaced)

    2. Call tech service (424-272-6998) for additional help.  Please have the model and serial number of your operator when you call.

  1. Edward's picture
    Mar 05, 2020

    The green photo eye blinks and is not solid. The red led has a weak glow. There’s no obstruction and I can’t seem to align the photo eyes. If I put the photo eyes closer, the red eye has a better solid. Do I need new photo eyes?

  1. Brian's picture
    Sep 30, 2019


    The issue you describe is often related to a stuck relay.  With the handle of a screwdrive, giive the back panel where the buttons are located a couple of firm taps.  This could free the relay.  If this does not work, call tech service 424-272-6998 for more assidtance

  1. George's picture
    Oct 17, 2020

    Dude you are the man who would have thought tapping this thing like a starter on a car would do the trick. I was wondering why it kept beeping and not sending the pulley forward I thought I really messed it up but thanks a lot

  1. Robby's picture
    Jun 23, 2021

    Holy Cow. Two taps with a rubber mallet Boom,works fine now. Thank you fellas.

  1. Mike M.'s picture
    Sep 14, 2019

    I found my manual and it states door travels at abnomal speed for the 12 slow beeps but it doesn't say how to fix this issue. I also tried moving the door with the up/down limit set approach. The belt will move up but not down. hmmm...

  1. Brian's picture
    Jul 01, 2019


    Please call 424-272-6998 for troubleshooting assistance.

  1. Nigel's picture
    Jun 29, 2019

    My garage won’t open or close when I use the remote and the push pad.

  1. Brian's picture
    Feb 27, 2019

    Hi Lee,

    1. Most photo-eye (PE) issues are due to mis-alignment.  Loosen the wing nuts on the PEs and make adjustments until steady green and red LEDs can be see.  If this does not work, follow the process on the linked file to determine the source of the problem.

    2. Staples will often, over time, cut through bell wires causing shorts and system malfuntion.  Materials will expand and contract with changing temperature, humidity and other environmental conditions, so an issue like this tends to happen more in the winter and summer.  Bell wire sould be replaced.

    3. Your door can be closed by the operator by pressing and holding the push button control.  This is a line-of-sight overide in case the PEs malfunction.  All garage door openers have this function.  

    Follow the steps in the troubleshooting guide to isolate and solve the issue.  If you have additional questions, please call a professional garage door opener technician or 424-272-6998. 


  1. lee's picture
    Feb 26, 2019

    garage wont close, and I just notice one of the sensors is not showing a lights burn out? unit is about a year old and this is the first problem.

  1. Brian's picture
    Jan 23, 2019


    That could be a possibility.  If your photo-eyes do not look like the photo-eyes on this link it would be the case.  Replace the photo-eyes immediately with Guardian photo-eyes GUAT-201.  The old photo-eyes will not be dependable and may not reverse the operator when the IR beam is broken. 

     Call 424-272-6998 to troubleshoot further.

  1. Drew's picture
    Jan 19, 2019

    Both eyes are green. Not one red & one green. Any ideas? I’m thinking old eyes were left from previous opener? Help!

  1. Brian's picture
    Jun 25, 2021


    Please call 424-272-6998 with a photo of the photo-eyes.  There are cases in which the operator is replaced, but old photo-eyes remain.  Photo eyes from differnent manufacturers will not work. 

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