KDE black screen ("no signal") after turning monitor off/on

General system
1

Greetings, I have an interesting problem with my monitor losing signal after turning monitor off/on. It only happens when logged in to KDE Plasma or wake from sleep, otherwise OK:

  • Works OK in Grub menu (turn off/on monitor gives normal signal)
  • Works OK on KDE login screen (turn off/on monitor gives normal signal)
  • When logged in to KDE desktop or wake from sleep gives “no signal” on the monitor after turning it off then on
  • Same problem if I lock the screen in KDE, then turn monitor off/on

The only way to resolve the problem is to disconnect/reconnect the HDMI cable.

Any ideas what could be causing this or further troubleshooting tips? Based on the above tests, I don’t think it’s a HW issue but something going on with the KDE Desktop…

INXI 
System:
  Kernel: 5.15.13-arch1-1 x86_64 bits: 64
    Desktop: KDE Plasma 5.23.5 Distro: EndeavourOS
Machine:
  Type: Desktop System: Micro-Star product: MS-7C84 v: 1.0
    serial: <superuser required>
  Mobo: Micro-Star model: MAG X570 TOMAHAWK WIFI (MS-7C84)
    v: 1.0 serial: <superuser required>
    UEFI: American Megatrends LLC. v: 1.83 date: 09/26/2021
CPU:
  Info: 12-core model: AMD Ryzen 9 5900X bits: 64
    type: MT MCP cache: L2: 6 MiB
  Speed (MHz): avg: 2608 min/max: 2200/4950 cores: 1: 3599
    2: 2876 3: 2722 4: 2876 5: 2966 6: 3221 7: 2199 8: 2199
    9: 2195 10: 2196 11: 2198 12: 2196 13: 3599 14: 2875
    15: 2879 16: 2879 17: 2869 18: 2873 19: 2197 20: 2198
    21: 2198 22: 2199 23: 2198 24: 2199
Graphics:
  Device-1: NVIDIA GA102 [GeForce RTX 3090] driver: nvidia
    v: 495.46
  Display: x11 server: X.Org 1.21.1.3 driver:
    loaded: nvidia unloaded: modesetting resolution: 3840x2160
  OpenGL: renderer: NVIDIA GeForce RTX 3090/PCIe/SSE2
    v: 4.6.0 NVIDIA 495.46
Audio:
  Device-1: NVIDIA GA102 High Definition Audio
    driver: snd_hda_intel
  Device-2: AMD Starship/Matisse HD Audio
    driver: snd_hda_intel
  Sound Server-1: ALSA v: k5.15.13-arch1-1 running: yes
  Sound Server-2: PipeWire v: 0.3.43 running: yes
Network:
  Device-1: Realtek RTL8125 2.5GbE driver: r8169
  IF: enp38s0 state: up speed: 1000 Mbps duplex: full
    mac: d8:bb:c1:38:44:e0
  IF-ID-1: wg-mullvad state: unknown speed: N/A duplex: N/A
    mac: N/A
Bluetooth:
  Device-1: Intel AX200 Bluetooth type: USB driver: btusb
  Report: rfkill ID: hci0 rfk-id: 0 state: down
    bt-service: disabled rfk-block: hardware: no software: no
    address: see --recommends
Drives:
  Local Storage: total: 1.36 TiB used: 41.06 GiB (2.9%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 980 PRO 1TB
    size: 931.51 GiB
  ID-2: /dev/nvme1n1 vendor: Samsung
    model: SSD 960 EVO 500GB size: 465.76 GiB
Partition:
  ID-1: / size: 448.43 GiB used: 41.06 GiB (9.2%) fs: ext4
    dev: /dev/nvme1n1p2
  ID-2: /boot/efi size: 299.4 MiB used: 296 KiB (0.1%)
    fs: vfat dev: /dev/nvme1n1p1
Swap:
  ID-1: swap-1 type: partition size: 8.8 GiB
    used: 0 KiB (0.0%) dev: /dev/nvme1n1p3
Sensors:
  System Temperatures: cpu: 39.0 C mobo: N/A
  Fan Speeds (RPM): N/A
Info:
  Processes: 394 Uptime: 12m Memory: 31.34 GiB
  used: 3 GiB (9.6%) Shell: Bash inxi: 3.3.11
2

Update, I changed the HDMI cable, problem is resolved… Note that the first cable I used was the one included with the monitor (ACER Predator), which should be a “4k high speed, hi quality” cable. It would be really interesting to know what’s wrong with the first cable. Maybe no so “high quality” after all…

3

Lot of cables are not good and cause these kinds of issues.

1 Like
4

Interesting, I’m running 4k 120 Hz, maybe the KDE login screen runs in 60 Hz and therefore it worked? I.e. that the cable was not up to pair to handle 4k 120 Hz?

5

Where did you get the other cable? You bought a new one or switched it with another you already had?

6

Now I noticed that I did have KDE in 4k 60Hz, this caused issues with the old cable but not with the new (new cable was included with an XBOX X). But, if I change to 120Hz the problem is back even with the new cable. So I guess I need to get a good cable that can manage 4k 120Hz…

7

Yes it has an ultra high speed Hdmi cable. Which is 8K capable

Edit:

8

OK, did some more tests as follows:

  • In Windows, there is no issues running at 4k 120 Hz and turn the monitor off/on. This indicates that the cable is indeed OK.

  • Booted the EnOS Live USB (with nVidia). In this XFCE sesssion, I get the same issue (at 120 Hz), no signal after turning monitor off/on. When reconnecting the HDMI cable, signal is back, but XFCE reverted to 60 Hz. This is not the case with KDE, there 120 Hz is kept after reconnecting the cable.

Any ideas, do you think this is a nVidia driver issue? Any debug logs or similar that could give any more insights?

9

Honestly i don’t know. I would have to go through the same steps as you are doing to try to figure it out. I never use Windows to when trying to isolate an issue. The cables are different. If you are comparing the exact same cables it works on Windows and doesn’t on Linux then I’d agree it’s not the cable.

10

Did you check your journalctl and dmesg for any relevant messages?

11

I have now looked at the journalctl and dmesg output, this may indeed give some more insights to what’s going on.

  1. Turn off monitor, no messages in journalctl or dmesg.
  2. Turn on monitor, still no messages, screen is black with “no signal”.
  3. Replug HDMI cable, this outputs the below stuff in journalctl and monitor signal and picture comes back.

It looks like replugging the cable forced some update of screen settings…?

journalctl output 
an 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  EDID
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  1
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  EDID
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  1
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  CTM
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  CTM
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 65535
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 1 
                                                              Primary: true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 1 
                                                              Primary: true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Emitting configChanged()
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandR::setConfig
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Requested screen size is QSize(0, 0)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Needed CRTCs:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Actions to perform: 
                                                              Primary Output: true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:                 Old: 446 
                                                                      New: 0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Change Screen Size: true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:                 Old: QSize(3840, 2160) 
                                                                      Intermediate: QSize(3840, 2160) 
                                                                      New: QSize(0, 0)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Disable outputs: true
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:                  (446)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Change outputs: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Enable outputs: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: RRSetCrtcConfig (disable output) 
                                                              CRTC: 440
jan 13 19:28:30 linux pipewire-media-session[1155]: ms.mod.default-profile: device 'alsa_card.pci-0000_2d_00.1': can't restore profile: No such device
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Result: 0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 1 
                                                              Primary: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Disconnected output 446 from CRTC 440
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: RRSetOutputPrimary 
                                                              New primary: 0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: RRSetScreenSize 
                                                              DPI: 139.959 
                                                              Size: QSize(0, 0) 
                                                              SizeMM: QSize(0, 0)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandR::setConfig done!
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_CrtcChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Geometry:  0 0 0 0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 65535
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_CrtcChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Geometry:  0 0 0 0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 65535
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Disconnected"
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:30 linux plasmashell[975]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_2f_00.4.iec958-stereo.monitor"
jan 13 19:28:30 linux kwin_x11[878]: kwin_core: Failed to update gamma ramp for output KWin::X11PlaceholderOutput(0x7fd364027710, name="Placeholder-0", geometry=QRect(0,0 3840x2160), scale=1)
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 1 
                                                              Primary: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 1 
                                                              Primary: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 1 
                                                              Primary: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 1 
                                                              Primary: false
jan 13 19:28:30 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = false , enabled = false
jan 13 19:28:31 linux kded5[873]: kscreen.kded: Config does not have at least one screen enabled, WILL NOT save this config, this is not what user wants.
jan 13 19:28:31 linux kscreen_backend_launcher[987]: kscreen.xrandr: Emitting configChanged()
jan 13 19:28:31 linux kded5[873]: kscreen.kded: Config does not have at least one screen enabled, WILL NOT save this config, this is not what user wants.
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  CTM
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Property:  CTM
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         State (newValue, Deleted):  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 65535
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 1 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 0 
                                                              Primary: false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 0 
                                                              MODE: 0 
                                                              Connection: 0 
                                                              Primary: false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = false
jan 13 19:28:33 linux kwin_x11[878]: kwin_core: Failed to update gamma ramp for output KWin::X11PlaceholderOutput(0x7fd364002700, name="Placeholder-0", geometry=QRect(0,0 3840x2160), scale=1)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Emitting configChanged()
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandR::setConfig
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Requested screen size is QSize(3840, 2160)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Needed CRTCs:  1
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Actions to perform: 
                                                              Primary Output: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:                 Old: 0 
                                                                      New: 446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Change Screen Size: false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Disable outputs: false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Change outputs: false
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Enable outputs: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:                  (446)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: QMap((440, XRandRCrtc(0x55bb9470f480))(441, XRandRCrtc(0x55bb9470f660))(442, XRandRCrtc(0x55bb9470ee30))(443, XRandRCrtc(0x55bb9470b910)))
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Testing CRTC 440 
                                                              Free: true 
                                                              Mode: 0 
                                                              Possible outputs: QVector(444, 445, 446, 483, 484, 485, 486, 487) 
                                                              Connected outputs: QVector() 
                                                              Geometry: QRect(0,0 0x0)
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: RRSetCrtcConfig (enable output) 
                                                              Output: 446 ( "HDMI-0" ) 
                                                              New CRTC: 440 
                                                              Pos: QPoint(0,0) 
                                                              Mode: KScreen::Mode(Id: "449" , Size: QSize(3840, 2160) @ 119.88 ) Preferred: "447" 
                                                              Rotation: KScreen::Output::None
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr:         Result:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc QObject(0x0) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 0 
                                                              Primary: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Connected output 446 to CRTC 440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: RRSetOutputPrimary 
                                                              New primary: 446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandR::setConfig done!
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_CrtcChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Geometry:  0 0 3840 2160
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux plasmashell[975]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_2f_00.4.iec958-stereo.monitor"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_CrtcChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Geometry:  0 0 3840 2160
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRScreenChangeNotify
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Window: 39845893
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Root: 492
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size ID: 0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Size:  3840 2160
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         SizeMM:  702 392
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper: RRNotify_OutputChange
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Output:  446
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         CRTC:  440
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Mode:  449
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Rotation:  "Rotate_0"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Connection:  "Connected"
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xcb.helper:         Subpixel Order:  0
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 0 
                                                              Primary: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 0 
                                                              Primary: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 0 
                                                              Primary: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: XRandROutput 446 update 
                                                              m_connected: 0 
                                                              m_crtc XRandRCrtc(0x55bb9470f480) 
                                                              CRTC: 440 
                                                              MODE: 449 
                                                              Connection: 0 
                                                              Primary: true
jan 13 19:28:33 linux kscreen_backend_launcher[987]: kscreen.xrandr: Output 446 : connected = true , enabled = true
jan 13 19:28:34 linux kscreen_backend_launcher[987]: kscreen.xrandr: Emitting configChanged()
12

if it’s a kscreen issue you could try to reset it by deleting the config folder. Or just move it to create a backup so you can move it back if you need to.

mv ~/.local/share/kscreen ~/.local/share/kscreen.backup

Not sure if a relog is sufficient or if you need to reboot for it it to take effect though. Probably best to reboot just to be sure.

13

After removing the config folder, I did a reboot and confirmed that the folder was recreated with a fresh config, but the same problem persists…

14

Before plugging and replugging can you can switch framebuffers?
ctrl+alt+F3 and if you get a login prompt try go back? ctrl+alt+F1
and if that works does that give any additional messaging in journal?

Have you tried Displayport instead of HDMI?

15

More troubleshooting log is in /var/log/Xorg.0.log (or similar).
Maybe post it in a pastebin for inspection (after having done un/plugging cables).

1 Like
16

Here are some more tests as suggested by KDen and petsam.

  1. Switching frambuffer did indeed bring back the signal! CTRL+ALT+F3 give login TTY (screen wakes up OK), and CTRL+ALT+F1 switches back to normal desktop.

  2. Doing this operation outputs the following in Xorg.0.log:

[   291.054] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[   291.054] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[   291.054] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[   291.054] (--) NVIDIA(GPU-0): 
[   291.236] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[   291.236] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[   291.236] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[   291.236] (--) NVIDIA(GPU-0): 
[   291.711] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[   291.711] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[   291.711] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[   291.711] (--) NVIDIA(GPU-0): 
[   291.775] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[   291.775] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[   291.775] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[   291.775] (--) NVIDIA(GPU-0): 
[   317.052] (--) NVIDIA(GPU-0): DFP-0: disconnected
[   317.052] (--) NVIDIA(GPU-0): DFP-0: Internal DisplayPort
[   317.052] (--) NVIDIA(GPU-0): DFP-0: 2670.0 MHz maximum pixel clock
[   317.052] (--) NVIDIA(GPU-0): 
[   317.053] (--) NVIDIA(GPU-0): DFP-1: disconnected
[   317.053] (--) NVIDIA(GPU-0): DFP-1: Internal TMDS
[   317.053] (--) NVIDIA(GPU-0): DFP-1: 165.0 MHz maximum pixel clock
[   317.053] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[   317.113] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[   317.113] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): DFP-3: disconnected
[   317.113] (--) NVIDIA(GPU-0): DFP-3: Internal DisplayPort
[   317.113] (--) NVIDIA(GPU-0): DFP-3: 2670.0 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): DFP-4: disconnected
[   317.113] (--) NVIDIA(GPU-0): DFP-4: Internal TMDS
[   317.113] (--) NVIDIA(GPU-0): DFP-4: 165.0 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): DFP-5: disconnected
[   317.113] (--) NVIDIA(GPU-0): DFP-5: Internal TMDS
[   317.113] (--) NVIDIA(GPU-0): DFP-5: 165.0 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): DFP-6: disconnected
[   317.113] (--) NVIDIA(GPU-0): DFP-6: Internal DisplayPort
[   317.113] (--) NVIDIA(GPU-0): DFP-6: 2670.0 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.113] (--) NVIDIA(GPU-0): DFP-7: disconnected
[   317.113] (--) NVIDIA(GPU-0): DFP-7: Internal TMDS
[   317.113] (--) NVIDIA(GPU-0): DFP-7: 165.0 MHz maximum pixel clock
[   317.113] (--) NVIDIA(GPU-0): 
[   317.181] (II) NVIDIA(0): Setting mode "HDMI-0: 3840x2160_120 @3840x2160 +0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0}"

Using DP works without problem, but that port is used for my work laptop that has an old HDMI only allowing 4k at 30Hz. Therefor I need to use DP for that machine to get 4k 60Hz. I choose this specific monitor partly because it has both HDMI 2.1 and DP inputs :thinking:

17

Just replugging the HDMI cable gives the following output in Xorg.0.log:

[  1067.231] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[  1067.231] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[  1067.231] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[  1067.231] (--) NVIDIA(GPU-0): 
[  1067.293] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[  1067.293] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[  1067.293] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[  1067.293] (--) NVIDIA(GPU-0): 
[  1067.766] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[  1067.766] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[  1067.766] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[  1067.766] (--) NVIDIA(GPU-0): 
[  1067.829] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[  1067.829] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[  1067.829] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[  1067.829] (--) NVIDIA(GPU-0): 
[  1078.679] (--) NVIDIA(GPU-0): DFP-2: disconnected
[  1078.679] (--) NVIDIA(GPU-0): DFP-2: Internal TMDS
[  1078.680] (--) NVIDIA(GPU-0): DFP-2: 165.0 MHz maximum pixel clock
[  1078.680] (--) NVIDIA(GPU-0): 
[  1079.397] (II) NVIDIA(0): Setting mode "NULL"
[  1086.815] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): connected
[  1086.815] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): Internal TMDS
[  1086.815] (--) NVIDIA(GPU-0): Acer XB323QK NV (DFP-2): 42666.7 MHz maximum pixel clock
[  1086.815] (--) NVIDIA(GPU-0): 
[  1087.572] (II) NVIDIA(0): Setting mode "HDMI-0: 3840x2160_120 @3840x2160 +0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0}"
18

hmm, it could power management related. I don’t have KDE running right now so can’t look. But check your display settings and power management settings. Try completely disabling any power management and any energy saving features. If it works completely disabled you can always work to narrow down which setting is affecting things later.

You can also try turning off dpms with xset -dpms some DE settings may automatically re-enable it though. You can check its current status with xset -q | grep DPMS. Screen blanking may also be something to look into. You can try xset s off to turn screensaver off xset s noblank to turn blanking off.

You can also look into acpi issues. You could try turning it completely off in your grub config command line with acpi=off.

There are also xorg conf flags that you could look into. You can check this post for those: https://bbs.archlinux.org/viewtopic.php?id=262207

You could also try determining if its KDE issue or hardware/driver issue by installing a window manager and logging into it instead of KDE. Awesome comes with a bar and right click menu so no configuring needed for testing purposes.

19

This is a known behavior on Plasma. IIRC it is worked around with a service that restarts plasma and/or kwin after sleep.
Check at Archwiki power management for this kind of service and do some tests.

You may also test this, creating custom keyboard shortcuts for plasma restart and kwin restart and use them when you have the issue.

Xorg logs are needed in complete, use a pastebin service, as in the post it is difficult to inspect them. But I believe the restart service will solve your problem nevertheless.

20

Thanks for the suggestions, I will look into this and report back. Here are the complete Xorg logs:

Xorg.0.log
https://pastebin.com/QhB3KqBk

Xorg.log.0.old
https://pastebin.com/64a2aHpg