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I want to setup a dual-monitor system on Kubuntu 15.10. I have an NVIDIA GF119 [GeForce GT 520] graphics card that I had previously used with an Acer AL2223W monitor at 1680x1050 with no detectable problems. I tried to add an Ancor Communications Inc ASUS VS238 at 1920x1080 as the second monitor. However, I can't get both monitors to work at the same time.

When my login screen appears, it looks like a full-sized login screen placed behind a slightly smaller login screen. I assume that X (or xrandr, or whatever) generates both displays, but puts them both at (0,0) instead of one at (0,0) and the other to the left or right.

Once I log in, one screen turns black. However, if I move the cursor to that screen, it shows up, albeit as the X-shaped cursor that X apparently uses as default. Interestingly, if I start an application from KDE and thus, get the little bouncing icon indicating that the program is loading, it shows up on the black monitor. If I move the pointer to the black monitor, it appears below the cursor as usual, but it also shows up when the pointer is on the working monitor, as if the cursor were at the coordinates on the black screen that it is at on the working screen.

When I open nvidia-settings with sudo, the X Server Display Configuration shows that NVIDIA can detect both monitors and has them aligned as I want them. Currently, "X screen 0" is positioned absolutely at +0+0 and "X screen 1" is positioned absolutely at +1920+0; the ASUS monitor uses configuration "X screen 0" and the Acer monitor uses "X screen 1". Xinerama is disabled. I've attempted changing the monitors' positioning from Absolute to Right of/Left of, then saving the X configuration, but when I restart X, the changes are gone.

When I open KDE System Settings → Display and Monitor, it only shows one display. That single display works fine, at least.

xrandr only lists one connected screen; all other ports are disconnected. The single screen it lists is correct. Presently, the output is

Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm
   1920x1080     60.00*+
   1680x1050     59.95  
   1440x900      59.89  
   1280x1024     75.02    60.02  
   1280x960      60.00  
   1280x800      59.81  
   1280x720      60.00  
   1152x864      75.00  
   1024x768      75.03    70.07    60.00  
   800x600       75.00    72.19    60.32    56.25  
   640x480       75.00    59.94  
HDMI-0 disconnected (normal left inverted right x axis y axis)

I've tried adding a screen to xrandr manually with --newmode and --addmode, but I was unsuccessful; there's a good chance that I didn't do it right for my version of xrandr. According to xrandr -v, my xrandr program version is 1.4.3 and the Server reports RandR version 1.4.

My graphics card has one port each for VGA, DVI, and HDMI. I've tried putting the ASUS on HDMI with the Acer on DVI, then putting the ASUS on DVI with the Acer on VGA. However, the only two differences in the setups is which screen is working and which screen is black, and which screen shows the boot information before X starts up.

My current xorg.conf:

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 352.39  (buildmeister@vm-ubuntu1404-x64-001)  Fri Aug 14 21:52:24 PDT 2015

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 "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: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Ancor Communications Inc ASUS VS238"
    HorizSync       24.0 - 83.0
    VertRefresh     50.0 - 75.0
    Option         "DPMS"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "Acer AL2223W"
    HorizSync       31.0 - 81.0
    VertRefresh     56.0 - 75.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GT 520"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GT 520"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "metamodes" "DVI-I-1: nvidia-auto-select +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" "VGA-0: nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Incidentally, my InputDevices work just fine.

Please let me know if additional information could be helpful.

closed as off-topic by user.dz, Fabby, Eric Carvalho, kos, David Foerster Feb 2 '16 at 19:29

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This describes a problem that can't be reproduced that seemingly went away on its own or was only relevant to a very specific period of time. It's off-topic as it's unlikely to help future readers." – user.dz, Fabby, Eric Carvalho, kos, David Foerster
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    The problem vanished. I tried switching from my NVIDIA card to my motherboard's built-in video card, to see if I could get multi-monitor support that way. Like a fool, I forgot to install the drivers for the motherboard's card, so of course nothing showed on either monitor after the switch. However, when I switched back, both monitors work in a dual-screen setup. I had to switch their positioning in nvidia-settings, but that was trivial. I'm not marking this answered, because I have no idea what caused the problem or solution. Plus, the problem could recur when I reboot my computer. – Jacob M. Carson Jan 4 '16 at 20:10