Second/external monitor not working

when I attach a monitor to my laptop under KDE via HDMI, a kscreen window is popping up, where I can select screen configuration (left right, …), but there is no effect.

jornalctl shows:

Apr 09 16:07:25 legion dbus-daemon[2125]: [session uid=1000 pid=2125] Activating via systemd: service name='org.kde.kscreen.osdService' unit='plasma-kscreen-osd.service' requested by ':1.9' (uid=1000 pid=2257 comm="/usr/bin/kded5 ")
Apr 09 16:07:25 legion systemd[2109]: Starting KScreen OSD service...
Apr 09 16:07:25 legion dbus-daemon[2125]: [session uid=1000 pid=2125] Successfully activated service 'org.kde.kscreen.osdService'
Apr 09 16:07:25 legion systemd[2109]: Started KScreen OSD service.
Apr 09 16:07:25 legion kscreen_osd_service[15712]: qrc:/qml/OsdSelector.qml:71:9: QML Heading: Binding loop detected for property "verticalAlignment"
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr: XRandR::setConfig
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr: Requested screen size is QSize(2560, 1600)
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr: Needed CRTCs:  1
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr: Actions to perform:
                                                                Priorities: false
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr:         Change Screen Size: false
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr:         Disable outputs: false
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr:         Change outputs: false
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr:         Enable outputs: false
Apr 09 16:07:45 legion kscreen_backend_launcher[2553]: kscreen.xrandr: XRandR::setConfig done!

output of xrandr before and after attaching the second monitor doesn’t show a difference.

how can I access the external monitor?
is there anything missing in the configuration/installation?

on my older laptop it worked “out of the box”

What is the behavior if you boot with the external display already connected and powered?

nothing happens. neither on the laptop, nor on the monitor.
if I unplug the HDMI cable after boot, the kscreen pops up gain.

is it possible that the laptop requires settings that can not be met by the monitor, eg. resolution?

Do you have the chance to verify the function of the monitor with the same cable on another laptop/computer? It is possible that the monitor input/connector is broken. Had that once.

if connected to a raspberry pi with the same cable, the monitor works.

if I connect a different (small 10") monitor to the laptop: same behavior.

“Same behavior” meaning same bad behavior, or same as when using pi?

Is this a HDMI-to-HDMI cable, or is some adapter involved? If same cable with the small monitor, it suggests a laptop problem is more likely than a cable problem, but another cable is probably easier to try. Quality of connectors varies among equipment, especially with cable ends.

same bad behavior.

it is a pure HDMI cable - no adapter.
additionally I attached the monitor to a Macbook via a USB-C to HDMI Adapter: the monitor immediately connected.

@suse_paul is this laptop a hybrid system? Can you show the output from inxi -Gxz

I don’t know what a hybrid system is.

inxi -Gxz

Graphics:
  Device-1: Intel TigerLake-H GT1 [UHD Graphics] vendor: Lenovo driver: i915
    v: kernel arch: Gen-12.1 bus-ID: 00:02.0
  Device-2: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q] vendor: Lenovo
    driver: N/A arch: Ampere bus-ID: 01:00.0
  Device-3: Syntek Integrated Camera type: USB driver: uvcvideo
    bus-ID: 3-6:2
  Display: x11 server: X.Org v: 1.21.1.4 with: Xwayland v: 22.1.5 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915
    resolution: 2560x1600~165Hz
  API: OpenGL v: 4.6 Mesa 22.3.5 renderer: Mesa Intel UHD Graphics (TGL GT1)
    direct render: Yes

@suse_paul dual graphics cards which you have… I would surmise that the hdmi is used by the Nvidia gpu which has no driver present…

So, is suse-prime and/or bbswitch installed?

Is there a system BIOS option to switch graphics cards?

I suspect installing the nvidia driver would help…

Oh, can you show the output from cat /proc/cmdline as well.

suse-prime was installed.
bbswitch was not - I installed it now.

I have to check for BIOS options.

cat /proc/cmdline 

BOOT_IMAGE=/boot/vmlinuz-5.14.21-150500.55.52-default root=UUID=17f5d916-723e-4adb-a2db-10fcdd565b32 resume=/dev/disk/by-uuid/7bf0e087-845a-4094-b105-61c53c72786e splash=silent preempt=full quiet security=apparmor mitigations=auto crashkernel=346M,high crashkernel=72M,low

which nvidia driver do I have to install?
this is what is currently installed:

@suse_paul no, bbswitch is old (and suse-prime for that matter) with newer Nvidia GPU’s…

I suspect that suse-prime’s installation has blacklisted the nouveau driver as it expects the nvidia rpm(s) to be installed.

In the first instance I would remove bbswitch and suse-prime, this clears the slate so to speak. You also need to then add the grub kernel option via YaST bootloader nosimplefb=0 reboot and check that inxi -Gxz output again and hopefully the nouveau driver is in use.

should I reinstall suse-prime after removing it?

@suse_paul no, infact add a lock for the moment after removal… zypper rm suse-prime bbswitch* then zypper al suse-prime bbswitch* then lets rebuild initrd as well, so run mkinitrd since your on Leap.

I don’t have mkinitrd

no difference with respect to the monitor after adding the bootloader option and rebooting.

cat /proc/cmdline 
BOOT_IMAGE=/boot/vmlinuz-5.14.21-150500.55.52-default root=UUID=17f5d916-723e-4adb-a2db-10fcdd565b32 resume=/dev/disk/by-uuid/7bf0e087-845a-4094-b105-61c53c72786e splash=silent preempt=full quiet security=apparmor crashkernel=346M,high crashkernel=72M,low nosimplefb=0 mitigations=auto
 inxi -Gxz

Graphics:
  Device-1: Intel TigerLake-H GT1 [UHD Graphics] vendor: Lenovo driver: i915
    v: kernel arch: Gen-12.1 bus-ID: 00:02.0
  Device-2: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q] vendor: Lenovo
    driver: N/A arch: Ampere bus-ID: 01:00.0
  Device-3: Syntek Integrated Camera type: USB driver: uvcvideo
    bus-ID: 3-6:3
  Display: x11 server: X.Org v: 1.21.1.4 with: Xwayland v: 22.1.5 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915
    resolution: 2560x1600~165Hz
  API: OpenGL v: 4.6 Mesa 22.3.5 renderer: Mesa Intel UHD Graphics (TGL GT1)
    direct render: Yes

@suse_paul ok so instead, run dracut -f --regenerate-all and reboot. It could also be the card is too new for the nouveau driver in the older kernel…

no change.

 inxi -Gxz

Graphics:
  Device-1: Intel TigerLake-H GT1 [UHD Graphics] vendor: Lenovo driver: i915
    v: kernel arch: Gen-12.1 bus-ID: 00:02.0
  Device-2: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q] vendor: Lenovo
    driver: N/A arch: Ampere bus-ID: 01:00.0
  Device-3: Syntek Integrated Camera type: USB driver: uvcvideo
    bus-ID: 3-6:3
  Display: x11 server: X.Org v: 1.21.1.4 with: Xwayland v: 22.1.5 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915
    resolution: 2560x1600~165Hz
  API: OpenGL v: 4.6 Mesa 22.3.5 renderer: Mesa Intel UHD Graphics (TGL GT1)
    direct render: Yes

@suse_paul can you check the initrd lsinitrd | grep nouveau.

Might need to install the closed source driver… Have a read here for the repository and install, you need tohe G06 packages. https://en.opensuse.org/SDB:NVIDIA_drivers

initrd: command not found

G06 drivers are installed:

@suse_paul the command was lsinitrd :wink:

So does inxi -Gxz show a driver in use?