Monitor blank after Fedora boot

Is it perhaps displaying on the second HDMI port?

Theo

Am 10.01.2024 um 11:59:36 Uhr schrieb Theo:

Not connected at boot and doesn't show something when I connect it.

I also can't connect both because I only have one HDMI to DVI cable and only one Mini HDMI to HDMI adapter.

Am 10.01.2024 um 14:18:15 Uhr schrieb Marco Moock:

I now tried booting with monitor on HDMI0 (not connected before), but the same situation occurs.

Not on an rPi just a PC, but I was recently having similar issues with Fedora37, which if not connected to the displayport monitor at boot time, wouldn't output to the monitor after switching KVM from laptop to the PC ...

Upgrading to Fedora40 /seems/ to have fixed the issue (only been done a couple of days, so not absolutely certain).

Am 10.01.2024 um 14:06:22 Uhr schrieb Andy Burns:

Does the Pi support Displayport? Is there a workaround?

No it doesn't, it's HDMI only.

Some DP outputs can switch into HDMI mode and drive HDMI monitors via a passive converter, but I'm not sure DP inputs can accept HDMI.

You'd need an active HDMI to DP converter.

But the fact it's working during boot suggests it's not a monitor incompatibility, since it can clearly drive the monitor to begin with.

One thought might be that the desktop is driving the monitor to some resolution it's not happy with - perhaps worth trying is to configure the output with some safe resolution like 640x480 and see if it accepts it.

Theo

Not directly, but adapters are cheap, e.g.

What version of Fedora is on the rPi?

That's the wrong way round, you need something like:

Theo

Turns out I actually searched for "DP source to HDMI sink" instead of "HDMI source to DP sink" ... I was a little surprised they were as cheap and easy as to find as that.

Am 10.01.2024 um 15:47:54 Uhr schrieb Andy Burns:

Fedora-Server-39-1.5.aarch64.raw.xz is the image I used.

Am 10.01.2024 um 20:03:30 Uhr schrieb Marco Moock:

I now tried Debian, same problem. Boot log is shown, after that screen blank.

That suggests the problem is that the monitor claims it can do such-and-such resolution, and then isn't happy when the Pi does it. Do you have a menu button on the monitor you can press and does it tell you the resolution, or does it say 'no signal' or 'out of range' or something?

I'd guess the solution is to configure the desktop environment to use a different resolution, but it will depend on the DE as to how you configure that from the command line without using the DE's settings UI (which you can't see).

You could also try xrandr after setting a $DISPLAY variable, something like:

$ export DISPLAY=:0 $ xrandr --mode 640x480

which should temporarily set the resolution to 640x480. Then you can get into the settings UI.

Note this is for X11 - I'm not sure what the equivalent is for Wayland.

Theo

You need a "helper" such as gnome-randr.py or gnome-randr-rust these are not part of Fedora

Am 11.01.2024 um 09:31:26 Uhr schrieb Theo:

I have now testet another monitor, in Debian all is fine. With Fedora, the problem still exists.

The monitor shows "no signal".

Am 11.01.2024 um 14:07:29 Uhr schrieb Marco Moock:

Can that issue come from the DVI to HDMI cable?

I don't have any HDMI compatible monitor at all, I only have some that have VGA/DVI and I have a simple adapter cable. Maybe the output after the boot isn't acceptable for the DVI monitor?

Single link DVI only goes up to 1080p. Maybe the monitor is declaring itself to support some higher resolution, and then balking when the Pi sends it? Or maybe the Pi is sending HDMI instead of DVI and the monitor can't handle that? The Pi can't do dual-link DVI but maybe the monitor is telling it to do a dual-link-only resolution?

There are some settings in config.txt and cmdline.txt that would be worth playing with:

Am 11.01.2024 um 20:50:14 Uhr schrieb Theo:

Monitor is ASUS VW22AT, 1680*1050.

Does that affected the booted OS?