[SOLVED] No HDMI video after user login in Debian 9 LXDE

Getting your soundcard to work, using Debian on non-i386 hardware, etc

[SOLVED] No HDMI video after user login in Debian 9 LXDE

Postby pmlpm » 2019-01-07 19:14

Dear all,

I've been trying to use my desktop computer to a new monitor using a DVI (desktop) to HDMI (monitor) cable. Unfortunately, I get no HDMI video output after I enter my user's credentials and the system starts loading the graphical interface, meaning I can get video output until then. (I'm not interested in getting audio output at this point.) Afterwards, I get a blank/black screen, which I can only get out of using CTRL-ALT-F2. Also, everything works fine using VGA.

I am using Debian 9, LXDE.

uname -a

Linux 4.9.0-8-amd64 #1 SMP Debian 4.9.130-2 (2018-10-27) x86_64 GNU/Linux

lspci

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV730 PRO [Radeon HD 4650]
01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] RV710/730 HDMI Audio [Radeon HD 4000 series]

I am using the proprietary drivers though I previously tried the open source ones as well.

Once in TTY2 mode, I don't know what to do to fix the problem. I tried generating a xorg.conf file but that didn't change anything. I also tried to find out more information using xrandr but I get the 'can't open display' error.

Any ideas on what might be happening with my system?
Last edited by pmlpm on 2019-01-11 08:10, edited 1 time in total.
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54

Re: No HDMI video output after user login in Debian 9, LXDE

Postby Head_on_a_Stick » 2019-01-07 19:38

pmlpm wrote:using xrandr but I get the 'can't open display' error

Try
Code: Select all
DISPLAY=:0 xrandr
"French riots get results! U lot are instagram zzzombies" — graffiti over Euston underpass
User avatar
Head_on_a_Stick
 
Posts: 8610
Joined: 2014-06-01 17:46
Location: /dev/chair

Re: No HDMI video output after user login in Debian 9, LXDE

Postby stevepusser » 2019-01-07 23:32

What AMD proprietary drivers are you talking about?
I have heard that the amdgpu-pro ones for Ubuntu offer nothing over the standard amdgpu ones in the repo.

Also, show us the output of
Code: Select all
apt policy firmware-amd-graphics


If that's newer AMD hardware, you may also need a backported kernel and driver stack.
The MX Linux repositories: Backports galore! If we don't have something, just ask and we'll try--we like challenges. New packages: Flightgear 2018.2.2, 4.19.13 kernel, wine-staging 4.0~rc4, Stellarium 0.18.3, VLC 3.0.5, Midori 7.0
User avatar
stevepusser
 
Posts: 10443
Joined: 2009-10-06 05:53

Re: No HDMI video output after user login in Debian 9, LXDE

Postby pmlpm » 2019-01-08 10:12

Thank you for the replies.

stevepusser:

The output is:

firmware-amd-graphics:
Installed: 20161130-4
Candidate: 20161130-4
Version table:
20180825+dfsg-1~bpo9+1 100
100 http://ftp.debian.org/debian stretch-backports/non-free amd64 Packages
*** 20161130-4 500
500 http://ftp.pt.debian.org/debian stretch/non-free amd64 Packages
100 /var/lib/dpkg/status

Head_on_a_stick:

I will try that later and report back my results.
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54

Re: No HDMI video output after user login in Debian 9, LXDE

Postby pmlpm » 2019-01-10 16:04

The output I got from entering DISPLAY=:0 was the following:

Invalid MIT-MAGIC-COOKIE-1 keyCan't open display :0

Any ideas on what this means or how I can get around this issue?
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54

Re: No HDMI video output after user login in Debian 9, LXDE

Postby Head_on_a_Stick » 2019-01-10 16:08

pmlpm wrote:Any ideas on what this means or how I can get around this issue?

Enter the error message into a search engine and try the suggestions from the stackexchange thread.
"French riots get results! U lot are instagram zzzombies" — graffiti over Euston underpass
User avatar
Head_on_a_Stick
 
Posts: 8610
Joined: 2014-06-01 17:46
Location: /dev/chair

Re: No HDMI video output after user login in Debian 9, LXDE

Postby pmlpm » 2019-01-10 17:24

Are you referring to any specific thread?
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54

Re: No HDMI video output after user login in Debian 9, LXDE

Postby pmlpm » 2019-01-10 18:15

I found out that this issue is apparently exclusive to LXDE since I was able to get video output using MATE and Openbox.

I had the idea to test this after reading the following thread: https://bbs.archlinux.org/viewtopic.php?id=199656
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54

Re: No HDMI video output after user login in Debian 9, LXDE

Postby pmlpm » 2019-01-11 07:59

I was able to solve the problem by deleting the LXDE-related configuration folders within the /home/"username"/.config/ folder, as suggested in: https://bbs.archlinux.org/viewtopic.php?id=199656

To be more specific, I deleted the lxpanel/, pcmanfm/, and autostart/ folders but I was only able to log in after deleting the last two.

I found out this could solve the problem since I was able to log in as root but not with my regular username.

Obviously, getting video to work after switching video cables should not be so complicated and this is probably something LXDE developers should look into.

Thank you for your help.
pmlpm
 
Posts: 6
Joined: 2019-01-07 18:54


Return to Hardware

Who is online

Users browsing this forum: No registered users and 6 guests

fashionable