Interactive Whiteboards

This topic contains 6 replies, has 3 voices, and was last updated by Andreas Ley Andreas Ley 8 months, 1 week ago.

  • Author
  • #15110
    Andreas Ley
    Andreas Ley

    Our school has multiple generations of ActivPanels installed. They are connected to two HDMI sources each: An Apple TV and a computer.

    On several (all?) panels of type AP4-84-4K, audio out stops working at some point. When this happens…

    • neither internal speakers nor headphone out will work (just silence)
    • all HDMI sources and ports are affected
    • disconnecting/reconnecting the sources doesn’t help
    • shutting the panel down (= red light) and turning it on again doesn’t help
    • using the physical switch on the back (disconnecting power) and restarting the panel DOES help and audio works again for a few days/weeks

    Is this a known problem? Is there a mainboard firmware upgrade available for this generation of ActivPanels?

  • #15113

    Hi Andreas Ley,

    Thank you for posting.

    There isn’t a known issue with the ActivPanels loosing sound.

    Are you using direct HDMI cables from the computer to the ActivPanel?
    When you loose sound, if you restart the computer does this work?
    Can you also help to confirm what OS version and build you are using?

    I look forward to your reply.

    Kind regards,
    Promethean Technical Support


    • #15136
      Andreas Ley
      Andreas Ley

      Hi Adam

      We’re using a direct HDMI cable from the Apple TV to the panel.
      The HDMI signal from the computer is usually passed through a document camera, but I’ve tried connecting it directly and that didn’t help.
      When the problem occurs, sound is lost from both HDMI sources (Apple TV and computer).

      Interestingly, even after losing sound from HDMI, the “click” noise when navigating the menu are still audible.

      SW Version: 1.1.7
      Panel: LC840EQD-SEM1

      Thanks for looking into this.

      Kind regards,

  • #15147

    Is any hardware connected to the SPDIF or headphone outputs on the Panel?  If so, please disconnect any cabling plugged in there.

    On the AppleTV, what is the Audio Format (Settings > Video and Audio > Audio Format) set to?  If PCM or LPCM is an option, choose that option.  Does this affect the audio playback?

    Is a similar loss of audio experienced when a USB drive with supported media on it is plugged into the MEDIA USB port on that Panel and played in the Panel’s Media Player?

    • #15148
      Andreas Ley
      Andreas Ley

      On some panels, an ActivSoundBar is plugged into the headphone output. On others, there is nothing plugged into the headphone out or the SPDIF out. The symptom occurs on all our panels of this generation. Other versions (AP2 and AP6) are not affected.

      On the Apple TV, audio is set to Stereo (this should mean 2-channel PCM only, no encoded audio).

      I haven’t tried playing media from an USB stick; I’ll do that next time audio out is lost.

  • #15152

    Hi Andreas Ley

    Thanks for posting.

    I will contact you further to help assist with this issue.

    Kind regards,

    Promethean Technical Support

  • #15450
    Andreas Ley
    Andreas Ley

    For those having similar issues: It seems we’re encountering issues with HDMI-CEC (a feature of HDMI designed to allow users to command and control devices connected through HDMI).

    Our Apple TV are sending CEC commands which the ActivPanel doesn’t (properly) process, leading to unexpected behavior.

    Our workaround at this time is disabling HDMI-CEC on the Apple TV (“Settings” -> “Remotes and Devices” -> “Home Theater Control” -> “Control TVs and Receivers” to “Off”).

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