LE 10.0.0 RPi4B - TV signal is lost

  • This issue was also present in LE10 RC1 so I stayed on BETA5 with the hope it wouldn't be present when the final 10 build came out. Alas it still is.


    When I updated to RC1 from BETA5, I immediately started watching a movie (1080p SDR). The TV signal started dropping out but would come back after a few seconds, no more than 10. After about 20 minutes of this happening 15-20 times I did some basic troubleshooting (rebooted, switched HDMI ports, tried another video file, changed HDMI cables) I reverted back to BETA5 and the issue was gone.


    With LE10 the TV signal is lost seemingly at random but does not come back.


    What I did:

    • Clean install LE10.
    • Kodi starts and is responsive for some time. I can get through the initial setup and start adding media sources, setup WebUI.
    • Restore backups of media databases via SSH. Reboot
    • After some time the TV signal is lost.
    • Reboot and it happens again.
    • I switch HDMI port and reboot. TV signal lost again after reboot.
    • I disconnected and reconnected the HDMI from both the RPi and the TV. TV signal lost again after reboot.
    • Clean install LE10 a second time.
    • Setup media sources manually and begin scanning for content.
    • After some time the TV signal is lost.
    • Reboot and it happens again.
    • Login to SSH and delete databases to start fresh. TV signal lost again after reboot.
    • Login to SSH and run pastekodi command: http://ix.io/3x5Z
    • Clean install LE10 a third time.
    • Kodi starts and displays the initial setup wizard. I left it there for a few minutes as I was typing this and the TV signal was lost.
    • I reboot, complete initial setup and run pastekodi command again: http://ix.io/3x6o
    • I try to setup media sources manually and TV signal is lost.

    At this time my LE installation is completely unusable. I have to reboot, either via SSH which takes an unusual amount of time (about a minute or so), or by power-cycling the RPi every time the TV signal is lost.


    I want to download the BETA5 to install on a separate microSD card so I can have a usable system when I'm not troubleshooting this. Is it still available somewhere?


    Edit: Attached dmesg console output

  • Your power-supply seems to be underrated. The logs show undervoltage reports which then cause the HDMI signal to drop out - and will likely cause all sorts of other issues.


    I'd recommend using the official RPi power supply, this is known to be working fine.


    so long,


    Hias

  • I will get the official RPi power supply and see if that solves it.


    Why would the issue appear only on RC1 and 10.0.0 though? If that were the case wouldn't the beta versions also have this issue?

  • Most likely you are hitting this issue: HDMI screen turns off when sustained high CPU usage on all cores · Issue #1598 · raspberrypi/firmware · GitHub


    Due to internal clocking changes the RPi4 started clocking down the HDMI block too much when it throttles (eg when it got too hot or in undervoltage conditions) which led to "no signal".


    LE 10.0.1 will contain a fix for that, but you still need to resolve the root cause (too weak power supply).


    LE 9.2 was able to visually notify you about undervoltage conditions (by showing a lightning bolt on the screen) but unfortunately that's no longer that case with the new graphics driver in LE10 so you/we need to check the logs (we added the throttled state to pastekodi logs right at the beginning though so we can easily see if there was a power supply issue - these are still quite common).


    so long,


    Hias

  • Thank you for the detailed explanation.


    I will leave the thread as unresolved for now, until I get the new power supply and check that the issue is resolved by it. It may be a few weeks as I live on an island and supplies/deliveries are short and also diminished due to COVID-19.