Adding CEC support to cheap HDMI grabber with 4K loop through and HDCP 2.2

  • Very easy!

    All you need is a soldering iron with a fine tip and maybe a magnifying glas.


    This is the link to the grabber on AliExpress: https://www.aliexpress.com/item/1005003604965409.html

    6996-img-6441-jpg


    It has 4K HDMI loop through and HDCP 2.2 support.

    Be warned though, it generates colour bars (rainbow signal) when there is no signal from HDMI.

    You can easily fixe the colour bar problem by activating "Signal detection" in Hyperion so it's not really a big deal.


    The big problem with this HDMI grabber is that the CEC signal is broken. No CEC is a dealbreaker for me but fortunately, it can be very easily fixed.


    What is HDMI CEC ?

    "HDMI-CEC (Consumer Electronics Control) is a function of the HDMI standard that allows connected devices to talk with each other. The aim of this feature is to allow you to control multiple devices connected to a display with one remote, increasing convenience."


    HDMI connectors have 20 pins and the CEC signal use pin 13 and pin 17.


    In the case of this HDMI grabber the trace for pin 17 already has continuity on the PCB between the HDMI IN and HDMI OUT.

    Pin 13 however doesn't have continuity. The trace is on the PCB but for some unknown reason, they left a small gap intentionally breaking the CEC signal.


    It is a very small gap easy to bridge with a steady hand, a soldering iron with a small tip and a magnifier.


    Look for a missing resistor (R12) shown by a red arrow in the next picture:

    6994-img-6436-jpg


    And here is a closer view:

    6995-img-6439-jpg


    In these pictures I have already fixed the gap.


    I have been using the grabber for about two weeks in my setup and it's been rock steady!


    Hopefully this helps someone!


    - Blaise

  • I bought a capture card from your link to aliexpress, today arived, is slightly different inside to your photo, don't have R12, but the good news is HDMI-CEC works out of the box!

  • I've had this grabber for a while already, but my old TV didn't support CEC, which is why I never even noticed that it wasn't working. Now I got a new one recently, of course with CEC, but as soon as I added the grabber to the loop, CEC stopped working. After trying some things, I started to look for a new grabber with integrated splitter that does support CEC, but instead stumbled across this thread - and all I can say is thank you blaisebarrette! A 2 minute job and it works perfectly.


    In case anyone is wondering - component size is 0402.

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