Black screen after login

[michaelfromlancs]

I am using Kubuntu 14.04 32bit. It was working fine until one day when I logged on and got a black screen. There is a lot of stuff on forums about problems with video cards but I don’t think that can be my problem since (a) it was working fine and (b) I can log on as “guest” and it still works fine. Here are the details.

The blue & purple screen appears with two possible users, myself and guest. I choose myself and enter the password. In turn each icon appears for the hard drive, wrench, internet, desktop screen and Kickoff launcher. The screen flickers (is this significant?). It stays with the 5 icons displayed for a few seconds, and then fades to black with a white arrow pointer which responds to mouse movement but nothing else.

I can get a terminal (tty1) running by pressing Ctrl+Alt+F1. I have to login again and can then issue commands. However, entering program commands such as kwrite (which is installed) fail with the response “cannot connect to X-server”. Firefox fails with the response “Glib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed Error: no display specified” I also tried startx. This takes me back to the blue & purple screen with the 5 icons appearing in sequence (again the screen flickers) which then fades to black as before. After doing this, a lot of messages appear in the terminal screen tty1, the last of which is “Suspending AIGLX clients for VT switch” but I cannot find any way of scrolling up this screen to see the initial message, nor can I find a way to copy the messages to a file.

If I switch off and then login as “guest”, the 5 icons appear (without any screen flicker) and the desktop loads as expected with the Kickoff launcher appearing at the bottom left. Programs can then be launched as usual, e.g Kwrite, Firefox.

I had hoped to leave Windows behind, but I am really stuck on this. I suppose I could reinstall 14.04, but what is the chance of it happening again, and I have installed various bits of software which I would have to reinstall, such as Latex, Fortran, Pascal, C++, and associated IDEs, Kile, Geany, FPC.

In case it helps, the PC is a Dell Vostro 200 Intel i686 with dual processors each 1Gb RAM, a 228 Gb internal hard drive, Intel graphics 82G33/G31 VGA compatible. (k)ubuntu 14.04.1 LTS, GNU/Linux 3.13.0-35-generic i686, KDE 4.13.3, GRUB legacy version. Linux is the sole operating system (i.e. not a dual boot).

It looks to me that some system parameter has got reset for myself as user, but I have no idea what this could be or even where to find it.

Any help would be appreciated. I am new to Linux, so please take it slowly.

[vinnywright]

I think you have messed up the ownership of files in your /home and have 2 options hear ...........................
first log back in to that TTY then do one of the following.
1-

sudo chown -R you:you /home/you

{where "you" is your user name},,,,,,,this will change the owner and group of all files and folders in your home to you ,,,,,which they should be .

2-

mv .kde .kde.old

this will rename your .kde folder to .kde.old ,,,,this is where most of your configs are ,,,,,,,when you try to login to the GUI next a new .kde will be created ,,,,,,,it will be a default one so any custamizing you have done will be gone (it's still in .kde.old) .

VINNY

[michaelfromlancs]

GREAT! Thanks for this. It worked fine. The only thing I am left wondering is what I did to create the problem. I really have no idea. The last thing I did before it happened was fiddling around with icons on the horizontal taskbar across the bottom of the screen. At least if it happens again I know what to do.

[vinnywright]

GREAT! Thanks for this. It worked fine. The only thing I am left wondering is what I did to create the problem. I really have no idea. The last thing I did before it happened was fiddling around with icons on the horizontal taskbar across the bottom of the screen. At least if it happens again I know what to do.

great ,,,glad it worked for you .

But this is linux land and exact details are usfull and necessary ,,,,,So whitch one of the 2 things did you do that worked for you .

as to how this happend ,,,, well let me ask ,,,have you been starting any GUI apps like dolphin with sudo to get a root app. .......this is usually how this happens .

if one has to use a GUI app as root it is best to use "kdesudo" .

VINNY

[michaelfromlancs]

I am rather embarrased to say that I misread your suggestions (which were admirably clear) and actually did both, so I am not sure which of the two did the trick. So far my use of sudo has been confined to updates and installing software. I don't recall starting any GUI apps with sudo, although it is possible I may have done so without realising it. However, I will certainly be on the lookout for this in the future. Thanks again for your help.