(Quick-note) Troubleshooting Dual Monitor Issues on KDE on Ubuntu/ Linux Mint

Diego Carrasco G. — Thu, 25 Jul 2024 07:00:00 GMT

TLDR

Learn how to troubleshoot and resolve issues with dual monitors on KDE, especially when one monitor stops working or remains off.

Context

By default, KDE handles dual monitors well on a new installation. However, sometimes one monitor might stop working and stay off. This happened to me, and I had to fix it using xrandr and KDE's display settings.

Steps

Here is how I resolved my issue:

Run xrandr Query:

xrandr --query

This showed two activated displays.

Copy Display Names: I identified display names from the xrandr output.

❯ xrandr --query
Screen 0: minimum 320 x 200, current 5120 x 1440, maximum 16384 x 16384
HDMI-A-0 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440    144.00*+ 120.00    99.95    59.95  
   3840x2160     30.00    25.00    24.00    29.97    23.98  
   1920x1200    144.00  
   1920x1080    120.00   119.88    60.00    60.00    50.00    59.94  
   1600x1200    144.00  
   1680x1050     59.88  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x960      60.00  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
DisplayPort-0 connected primary 2560x1440+2560+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
   1920x1200     59.95  
   1920x1080     60.00    50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   1600x1200     59.95  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1440x900      59.89  
   1280x960      60.00  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
DisplayPort-1 disconnected (normal left inverted right x axis y axis)

Execute Command:

xrandr --output HDMI-A-0 --mode 1920x1080 --right-of DisplayPort-0

I set HDMI-A-0 as the main display, right of DisplayPort-0.

Adjust in KDE Preferences: I went to Preferences > Display Configuration. I set the desired resolutions and applied the changes.
Fix Overlap: When there was overlap, I changed both monitors to a lower resolution, applied changes, then set the preferred resolution again.

Following these steps fixed my issue, and both monitors worked correctly.

Diego A. Carrasco Gubernatis | Personal Website (Posts about ubuntu)

(Quick-note) Troubleshooting Dual Monitor Issues on KDE on Ubuntu/ Linux Mint

TLDR

Context

Steps

References