Everything works with the rpi3. Why not with the rpi4?

Hello! I have been using LibreELEC with a Raspberry Pi 3 for several years without any issues. Recently, I decided to set up a second LibreELEC system for another TV in my home. The plan was to buy a new Raspberry Pi 4 to replace the current Pi 3 in my living room and use the Pi 3 with the second TV in a different location.

However, I encountered a problem when trying to get a picture with the Raspberry Pi 4 connected in place of the Pi 3, which was previously connected to my Denon amplifier and Samsung TV. Since it works with the Pi 3, I know that the HDMI cables, amplifier, and TV are functioning correctly.

I tried connecting the Raspberry Pi 4 directly to the TV, and it works fine that way. The issue seems to occur only when it is connected through the Denon amplifier.

I have tried various different settings in the config.txt file, but none of them have worked. One of the settings I attempted to use is:

hdmi_safe_mode=1

I also tried several other parameters in place of the above setting:

hdmi_force_hotplug=1 
hdmi_group=1 
hdmi_mode=16

I also tried to use hmdi boost (with 7 or but nothing works.

And also ignore the edid.

No luck at all.

In your opinion, if everything worked well with the raspberry pi 3, there must be a solution with the raspberry 4, right?

Thank you very much.

I didn't know that in the new version of LE, there is a new KMS driver, which explains why changing hdmi_param didn't make any difference.

I forgot to mention that my receiver is not 4K. I just want to be able to have 1080p for now.

So I booted my Pi without an SD card and this time, I saw the boot screen.

The display line is:

Quote

Display: DISPO0: HDMI HPD=1 EDID=OK #2 DISP1: HDP=0 EDID=none #0

Also, yesterday I was able to decode the EDID of my receiver via SSH, so I think the HDMI cable is working correctly.

Is there a way to force the Pi to boot in 1080p with the DKMS driver?

Thank you very much for your time!

I find some information on the forum to start by myself.

So here's my last test. I put this in my config.txt file:

dtoverlay=vc4-fkms-v3d,cma-515


hdmi_ignore_edid=0xa5000080
hdmi_ignore_cec_init=1
hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=16
#config_hdmi_boost=7
#hdmi_drive=2

but still no luck
(i've tried without ignore_edit, with config_hdmi_boost, and hdmi_drive=2 also)

Thank you VERY much for your time. It's working now!

Have a good day.