Atlona Help Center

KB01406 - How to learn EDID on a AT-UHD-CAT unit


Subject: How to learn EDID on a AT-UHD-CAT unit


Being an HDMI distribution amplifier, the AT-UHD-CAT will typically have a variety of displays connected to its outputs. To ensure optimal performance, the AT-UHD-CAT system’s EDID management has two EDID settings, INT (Internal) and LEARN. “INT” allows a user to select an internal EDID from the 17 options built into the unit (1080p 2ch is the factory setting):

This setting will typically provide optimal performance as long as all the sink’s (displays/projectors) have similar functions/features. However, in a system with a variety of display models/brands, video/audio playback issues can arise as the source device may output an EDID that not all outputs support.

Thus, the UHD-CAT also features EDID learning. This allows you to learn the unique EDID information from a display and allow the sources to cater to this EDID format. Most displays/projectors will support EDID that is not natively their own (if it is in a format they can support). Therefore, if you find you have issues in getting video on all outputs or that some outputs lose video periodically, it is recommended to perform an EDID learn.


EDID can be learned in two ways,


Method 1: Using the web-GUI or using the front panel of the UHD-CAT unit.


  1. To learn EDID using the web-GUI, you will need to gain access to the unit through the web interface. The process to accomplish this is found in this article.
  2. Once you have access to the web-GUI, click the EDID tab at the top banner and you will see the EDID settings:
  3. With the EDID mode set to INT, you can choose one of the 17 different EDID modes listed above.
  4. You can also use the EDID Copy button to learn EDID from the display/projector connected to the #1 output of the UHD-CAT unit (before doing an EDID learn, please confirm you have video showing on this output). You are also welcome to unplug the CAT cable from any of the other outputs and connect it to output 1.

If you want to lock the EDID from being changed when using the front panel, enable the EDID lock option which will only allow EDID to be changed via the web-GUI (unless the unit is factory reset via RS232 or TCP/IP). 


Method 2: Using the web-GUI or using the front panel of the UHD-CAT unit.

  1. Turn on the display/projector connected to output #1
  2. Confirm the output is showing video, if this output is not showing video, connect one of the other outputs until you see video show up from output #1
  3. With video passing to the sink device (display/projector) on output 1, press and hold the EDID button on the UHD-CAT until you see the LEARN LED flash: . After a few seconds, it will stop flashing and stay permanently lit, this means EDID was successfully learned. You can safely power cycle the unit, as long as the EDID button is not pressed, the unit will hold onto the “Learned” EDID.
  4. After performing the EDID learn, powercycle the UHD-CAT by removing power from it for 5 seconds and reconnect it. Confirm if video issues have been resolved.


If you have any issues with getting a stable video signal or permanently lit EDID light on the UHD-CAT unit, please try connecting another TV to output 1, making sure you have good video on the sink device and then repeating steps 1-3 again. 

If you have tried the steps above and continue to have issues in getting stable video, please contact Atlona technical support for more help.

 Article ID: KB01406 

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