rpi 4 with latest libreelec not showing on TV

Dear All,

I have an old TV, Acer AT4220 with 720p, to which I have had a Pi 3b connected succesfully in the past. However now that I replaced it with a pi 4b, I only get the boot message on the screen, then the KODI logo and then shortly the menu after that the system has loaded upon which I get some funny color blocks, and then the connection to the tv is lost.

I guess this has something to do with screen resolution or frequency?

I can ssh into the pi without issues, also while there´ is no connection to the tv.

http://ix.io/4zvN

Thanks!

That I put because it was in the config.txt of my old raspberry, forgot why it was there but now I have removed it. New pastekodi:

http://ix.io/4zvS

Thanks, the one I´m using is Highpi Pro universal case for the RPI 4

The setup works fine on my monitor, but I should perhaps add that there´s an Onkyo amp with HDMI inbetween the pi and the tv, so I will see if switching ports or bypassing the amp could provide a different result.

Btw, the tv´s resolution is not 1280x720p but in fact 1,366x768. Could this be the problem?

Quote from Da Flex

The AVR eventually sends a wrong HDMI mode to the TV, and interferes HDMI negotiation.

To avoid this, edit cmdline.txt, and append this to the end of the line:

Code

video=HDMI-A-1:1280x720@60D

Unfortunately that made no difference

The pi works fine with the case when connecting it to a monitor. I tried connecting it directly to the TV and got no image at all at any time. I will try to do that again next week, since I managed only to connect to one of the HDMI inputs because of cable length. Who knows if there´ is an issue with that input... I wanna rule out everything.

Some good news: I decided to reinstall libreelec one more time and connect the pi directly to the tv during the setup process. Previously I did this via my monitor.

This worked smoothly, and I even tested it afterwards to do the job well.

Unfortunately, when I assembled the case completely, meaning to attach the hifiberry board that I use with it and close the lid, something went wrong when I connected it again: The image was gone

I tried to take off both the lid and the hifiberry again, but the result was the same. Tried again on my monitor, but no luck.

My theory is that I broke something in the HDMI cable when pulling it in and out or perhaps when putting the case together, which required a hard slap on it, while the cable was still connected - obviously the power was off at that point.

I dare not trying with my other HDMI cable which is connecting another pi that I use as a thin client for my work computer elsewhere in the house, since I do not want to risk the same thing happening to that cable. I know these cables break very easily, so I guess I will order a new one and give it another try...
Anyway: The point must be that libreelec may be very fragile to whatever screen was used during setup, dont you think?

Quote from Da Flex

Nah, if you use the above cmdline.txt options, then it always starts with the same HDMI mode.

In fact, I did a reinstallation where everything looked as it should on the monitor untill I added video=HDMI-A-1:1280x720@60D to cmdline.txt. After that, I got no picture at all, not even after removing that line, so this is the point where I did another reinstallation. I did not try vc4.force_hotplug=1 at any point though.