RPi4B no Signal on Samsung TV after Switching Inputs

  • Hello,


    I read some other topics but its not exactly my Problem.

    I've read so far:




    Settings:

    ---------------

    Hardware:

    Libereelec 10 on Raspberry Pi4B 4GB

    Samsung 4K TV, 2020 Model

    Samsung Soundbar Q950T (which has 3 HDMI Ports: 2 Inputs, 1 Output)


    Cables:

    AmazonBasics HDMI 2.0 fast Ethernet Micro HDMI Cable

    also tested:

    AmazonBasics HDMI 2.0 Cable with Micro HDMI Adapter which is also HDMI 2.0 from UGREEN

    The Cable was formerly connected to an Odroid N2 and did 4k 60Hz without Problems.


    Connection:

    RPi4 HDMI Port 0 -> Samsung Soundbar HDMI 2 -> Samsung TV HDMI 2 (eARC)


    Software:

    distroconfig.txt:

    hdmi_enable_4kp60=1

    cec_osd_name=kodi

    hdmi_force_hotplug=1 (setting it to 0 or 1 has no impact on my problem)


    config.txt:

    hdmi_ignore_cec_init=1

    gpu_mem=256


    Target:

    ----------

    Having 4k 60Hz Picture on my Samsung 4K TV


    General Proof:

    ---------------------

    3840x2160p @ 60 Hz works with FireCube, so TV can.

    3840x2160p @ 60 Hz also works with RPi4B after fresh boot


    Problem Description:

    ------------------------------

    When I have chosen RPi4 Input and boot up the RPi I have Splash Screen, GUI comes up, TV shows I have 3840x2160p @ 60 Hz, everything good.

    -> So here we have proof that it works, I have basically no 4K Issue because I have GUI Running, can watch movies etc.

    BUT...


    1. Then I switch Input to FireCube which comes up with 3840x2160p @ 60 Hz

    2. Then I switch back to RPi4 (Kodi) -> No Signal

    3. Reboot Pi -> Signal in 4K is back


    Same behaviour is when I turn TV off and on again -> No Signal from RPi


    With FHD Settings in Kodi I don't have these issues. Its only in 4K Mode.


    Enhanced UHD Colors is activated on TV.


    My Feeling:

    -----------------


    I would assume kind of a negotiation Problem when switching back and forth as the Samsung shows pretty long the "loading" Circle and ends up in "No Signal, Check Source". As if the Pi needs to send kind of an init signal which does not come.


    Also strange is that even if I see a picture after rebooting the tvservice sais no "device attached"....


    Info:

    -------


    Kodi is on he whole time, I can reach it via ssh and it operates normal. (I also read about one guy who's kodi always crashed, thats not my problem)


    After freshly booted (GUI on the Screen) I have this output :D


    Code
    kodi:~ # tvservice -l
    0 attached device(s), display ID's are :


    After switched Inputs (no Signal), the same:

    Code
    kodi:~ # tvservice -l
    0 attached device(s), display ID's are :


    Created edid via:

    tvservice -d


    then


    edidparser


    output:


    I think the last line is relevant which is showing that all should work:

    Code
    HDMI0:EDID preferred mode remained as CEA (97) 3840x2160p @ 60 Hz with pixel clock 594 MHz



    So please I hope anyone can help!!

  • Hello, I have very similar issue with my RPi4b 4GB and LG4K TV model 2021


    Everything works fine only when TV is still running, once I switch off TV and than switch on again, there is message no signal and I have to reboot RPi4. This issue appears only with hdmi_enable_4kp60=1 flag in config.txt. Any idea how to fix this and having 4k 60Hz?

    No issues with 4k30 or FHD