[SOLVED] black screen only mouse pointer visible

[gnomek]

Today I did some updates, installed programs and some theme customization for gtk apps. When I restarted I can see only a black screen only mouse pointer visible and a notification from checkgmail that new email has come (on top of this black screen). The problem is that I have auto-login for this user and when I start PC I can see this Kubuntu wheel at first and then balck screen so I can't choose to log in to another (administrative) account.
When I press Ctrl+Alt+F2 I can do some terminal work though. Maybe I can save this installation somehow?
I tried:
$ kquitapp plasma-desktop
but I get: "kquitapp (2915) Cannot find application plasma-desktop by using servis org.kde.plasma-desktop and path /mainapplication."
when I type: plasma-desktop I get
QDbusConnection: session D-bus conncetion created before QcoreApplication. Application may misbehave.
plasma-desktop (2914) kuniqueapplication:cannot find d-bus session server:
"Unable to autolauch a dbus-deamon without a $display for x11"
plasma-desktop (2913) kuniqueapplication: pipe closed unexpectedly.

Are there any command that can revert any installations I made today from Muon or/and check status and repair all broken packages from Terminal?

Edit 1:

I installed Xfce and gdm and I logged in to xfce without problems and I can access Moun but how to recover KDE?
Muon doesn't show any broken packages.

[GreyGeek]

If you can use CTL+ALT+F2 to open a terminal try this

mv ~/.kde ~/.kde_old

and reboot. This will let KDE build a new config file. You'll have to restore settings in many of your apps.

[gnomek]

If you can use CTL+ALT+F2 to open a terminal try this

mv ~/.kde ~/.kde_old

and reboot. This will let KDE build a new config file. You'll have to restore settings in many of your apps.

This might work. I guess I could copy program's settings. I have just found that I can log into KDE to my administrative account. So the conclusion is that there are some settings in this broken account. But maybe there is a chance to recover not loosing all plasma and KDE settings? Perhaps this has something to do with x server and dbus?
I really spend a lot of time configuring Bespin and other settings.
Can't I just remove x server settings or something without loosing the rest? Of course I can go the proposed way eventually but I'd like to avoid any drastic movements.

[Snowhog]

By moving your .kde directory to .kde_old, you preserve everything you had. Rebooting recreates the new default .kde directory. The purpose behind this exercise is to prove or disprove that something within your users .kde directory is causing your problem. If logging back in (after having moved the original .kde directory) you don't experience the problem, then that is proof that something within the original .kde directory structure was the culprit. You can then take the steps to selectively copy specific files/directories from .kde_old back into your new .kde and restarting to test the results. You will eventually find the file/directory that causes your problem to reappear, and you have then discovered the culprit. Yes, this is a slow process, but it does work.

[gnomek]

I removed all packages that I recently installed including some themes for kde and gtk. I am still not sure what caused the problem.
The above mentioned procedure wasn't necessary but I will use it as a backup method before making any major changes to KDE. So, it is valuable lesson. Thank you.

Edit_1:
I found that this almost certainly has something to do with a mess with gtk themes in KDE.
http://forum.kde.org/viewtopic.php?f...on+look#p54622
Just a notice for those who will seek solution: check Ctrl+Alt+Backspace.

[GreyGeek]

....
Just a notice for those who will seek solution: check Ctrl+Alt+Backspace.

For those not familiar with Ctl+Alt+Bksp, the command to kill the xserver, and generally thows one back to the login screen, if autologin is not active. That sequence does not work unless it is checked in SystemSettings-->Input Devices --> Keyboard -->Advanced Tab.

[dmeyer]

For those not familiar with Ctl+Alt+Bksp, the command to kill the xserver, and generally thows one back to the login screen, if autologin is not active. That sequence does not work unless it is checked in SystemSettings-->Input Devices --> Keyboard -->Advanced Tab.

Yip, that's right, some people use SysRsq or something on older computers. An alternative is hitting Alt+Ctrl+F1 then just run

sudo pkill X

[SteveRiley]

For those not familiar with Ctl+Alt+Bksp, the command to kill the xserver, and generally thows one back to the login screen, if autologin is not active. That sequence does not work unless it is checked in SystemSettings-->Input Devices --> Keyboard -->Advanced Tab.

One of my favorites, which fortunately is already configured as a default global keyboard shortcut for the KDE Session Manager, is this:

Ctrl+Alt+Shift+PageDown

At the end of the workday, once I've saved everything, it's a curiously satisfying way to say goodbye