Atlona Help Center

KB01218 - Certain sources do not work either at all or at random times.

SKU: AT-UHD-PRO3 series matrix

Subject: Certain sources do not work either at all or at random times.


If a specific source is not working on the UHD-PRO3 matrix, this can be caused by a few different factors:

  • Source has issues passing video from its output à Try taking source to a display directly and see if it still drops (try using the same HDMI cable as being connected to the matrix)
  • Source has trouble reading EDID of the matrix system à See below for steps locking down EDID
  • Source is unable to get HDCP information to confirm signal path is safe to pass HDCP content onà See if this source is playing back HDCP content (i.e. a blu-ray movie) and try sending non-HDCP content (a DVD movie or the menu screen of the blu-ray player)
  • Source is too far away from the matrix (for HDMI cables longer than 25+ ft) à Try a shorter HDMI cable
  • Source is using an adapter that is outputting signal at a voltage that is too low for the UHD-PRO3 matrix to understand à Try another adapter, preferably from another brand
  • There is an issue with the HDMI cable being used to connect the source to the matrix à Try another HDMI cable (try a short cable under 10ft if possible)
  • The specific input of the matrix being used for that source has issues à Try moving the source to another input on the matrix
  • The source is not compatible with the specific display to which the source is being routed to à Try connecting the source to the display using the same HDMI port as connecting with the matrix
  • The signal the source is sending is too high bandwidth for the CAT cable to support (typically an issue in 4K playback) à See if a lower resolution on the source works. If so, check your CAT cable to ensure it supports adequate bandwidth
  • There is interference on the CAT line (EMI) causing video to drop out à Try moving the CAT line away from any electrical devices or try another cable on the ground
  • There are issues with the HDBaseT receiver being used (either hardware failure or issues with the connection from the matrix to the HDBaseT receiver) à Try another receiver from another output zone and see if issues follow


In many cases, sources that are unable to pass consistent video may be experiencing EDID communication issues. This is typically the cause of about 80% of video playback issues. One way to correct this issue is to perform an EDID adjustment.

  1. If one TV plays video more often than others (the issue is least likely to appear on it), consider learning EDID from this display and setting it to all inputs. For steps on how to learn EDID from a display, please see this article
  2. If all displays have the same issue at the same frequency of occurrence, consider learning EDID from one of them when it displays a stable video signal (even if for a minute). Capturing the EDID when the display is playing video should yield the proper EDID format that the source can then cater to.
  3. If all displays simply do not work with a particular source, but taking that source directly to the display passes video, consider using one of the internal EDID’s built into the matrix. To do this:


  1. Log into the web interface of the matrix, for steps on how to do this, please see this article
  2. Once you log into the web interface, click the EDID tab to access the EDID settings
  3. Once in the EDID tab, set all the inputs to one common EDID.
  4. Please consider using one of the EDID’s highlighted in the red box below as they are the most common ones:

Article ID: KB01218

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