Kubuntu 14.04 black screen after monitor off/on

Whenever I turned my display off and on again after having logged on,  the screen stayed black. After rebooting, the logon screen appeared, but after logon with my user account, the screen got black. Logging with other user accounts had no problem.

This problem occurred using Kubuntu 14.04.  and a Nvidia graphics card connected by a display port cable.

Here is the description how I corrected it. In short Change the first false value of your screen definition file  .kde/share/apps/kscreen/xxxxxxxxxxxxxx from false to true. Than make this file read only. In Detail Start one of the consoles: Ctrl-Alt-F1 Then enter your OS-User name and password. Go to the directory .kde/share/apps/kscreen located in your home directory: cd ~/.kde/share/apps/kscreen Listing the files in this directory (ls -1), should display at least one file, that looks like the one bellow. The files name is a mix of number an letters (seems a long hexadecimal number): ls -1 7134be4579e47853d9bc866485e252fb If you have/had more than one monitors, several files will be listed. This is a text file. Its contents can be displayed with the command cat : cat 7134be4579e47853d9bc866485e252fb [ { "enabled" : false, "id" : "9a9b7a71150d853203babd861f68d8c5", "metadata" : { "fullname" : "xrandr-Dell Inc.-DELL U2515H-9X2VY61E10XL", "name" : "DP-1" }, "mode" : { "refresh" : 59.9506, "size" : { "height" : 1440, "width" : 2560 } }, "pos" : { "x" : 0, "y" : 0 }, "primary" : true, "rotation" : 1 } ] Change the false value after "enabled" (from above) to true. Here I show how to do it using the vi editor, that is available on every Linux system. vi 7134be4579e47853d9bc866485e252fb Go to the beginning of false by using the arrow keys press the key [DEL] until false is completely deleted press the key [i] in order to enter the insert mode (-- INSERT -- will then by displayed at the bottom line) type true press the key [ESC] in order to leave the insert mode (-- INSERT -- disappear from the bottom line) press the keys [:] and [x] (":" starts the command mode and "x" is the command "exit with saving") If you display the contents of your file again, the false should now have been replaced by true Now the Graphical environment can be restarted by entering the command startx. startx

I could avoid that this problem occurs again I made this file read only chmod ugo-w 7134be4579e47853d9bc866485e252fb I hope this helps.

Tags: Problems&Solutions, Kubuntu, Publish, Monitor, Black Screen
August 28, 2016 at 08:52AM