Ubuntu – Built in display turned off with nVidia X Server Settings

displaydisplay-resolutiondriversnvidiaxorg

I've messed up.
I work on HP Pavilion dv6000 laptop with nVidia GeForce 8400M GS video card. I had a problem with resolution of my external display, and Ubuntu display manager hadn't seen the proper display's resolution, so I started to setting it up in nVidia X server Settings. I added X Screen 1 and saved to X Configuration file. I don't know how it happened, but somehow I turned off my built in display and I can't turn it on. After this occurred I updated video card driver, but the problem still exists.

nvidia-smi output:

+------------------------------------------------------+
| NVIDIA-SMI 340.102    Driver Version: 340.102        |
|----------------------------+-------------------+----------------------+
| GPU  Name     Persistence-M| Bus-Id     Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap|      Memory-Usage | GPU-Util  Compute M. |
|============================+===================+======================|
| 0  GeForce 8400M GS   Off  | 0000:01:00.0  N/A |                  N/A |
| N/A  65C   P0   N/A /  N/A |  234MiB /  255MiB |     N/A      Default |
+----------------------------+-------------------+----------------------+

+-----------------------------------------------------------------------+
| Compute processes:                                         GPU Memory |
|  GPU       PID  Process name                               Usage      |
|=======================================================================|
|    0            Not Supported                                         |
+-----------------------------------------------------------------------+

xorg.conf

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 361.42  (buildd@lgw01-18)  Tue Apr  5 14:33:28 UTC 2016


Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    Screen      1  "Screen1" RightOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"

    # HorizSync source: builtin, VertRefresh source: builtin
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "CRT-0"
    HorizSync       28.0 - 55.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Monitor"

    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "AU Optronics Corporation"
    HorizSync       30.0 - 75.0
    VertRefresh     60.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8400M GS"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8400M GS"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "nvidiaXineramaInfoOrder" "CRT-0"
    Option         "metamodes" "VGA-0: 1360x768 +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen1"
    Device         "Device1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "metamodes" "LVDS-0: nvidia-auto-select +0+0 {viewportin=1440x900}"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

My guess is that I should remove all the references to the Screen 1 from xorg.conf or restore this file to the original one. However the file xorg.conf.backup also isn't original, because I restarted the system multiple times while working on solving this problem.

Any ideas how to fix this problem or where to find the original xorg.conf file for the GeForce 8400M GS?

Best Answer

Switch to tty1 with strg + alt + f1, login and remove your /etc/X11/xorg.conf.

Then run sudo systemctl restart display-manager.service.

This will reset your settings and you can start configuring again.

You can also run nvidia-xconfig before restarting the display-manager which would create a default config for nvidia.

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