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. 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
    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. 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
    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. 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
    Jul 01, 2019


    Please call 424-272-6998 for troubleshooting assistance.

  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
    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. 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
    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. 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
    Apr 03, 2020

    Hi Eric,

    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
    May 03, 2020

    Hi Mike,

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

  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
    Jun 21, 2020

    Hi Harris,

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

  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
    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. 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 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. 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. 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. Brian's picture
    Aug 24, 2020

    Hi Terri,

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

  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. 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
    Sep 21, 2020

    Hi Stuart,

    Please call 424-272-6998 for troubleshooting help.

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