Black Screen on Login

I have serached around, but no fix could help me. Here's what happened:

A few days ago, for no reason, I couldn't see the login screen on my Ubuntu 12.04. nor do anything but reboot using CTRL+ALT+DEL. After reading some suggestions and experimenting, this is what I got so far:

• If I go to the recovery mode and then choose "resume normal boot" I can see the boot up text, and it stops at "Checking battery state".
• If I choose "failsafe graphics mode" it stops on a different point, one of the last messages being from xserver saying "fatal server error no screens found"
• I realized that I can get to the desktop if when the black screen appears I use CTRL+ALT+F1 and blindly type my username and password, and then use "startx". I get to my desktop, but no menus at all. At least I can use the terminal this way.
• I tried reinstalling xorg and nVidia drivers (using the current ones) but it didn't help
• I deleted the ~/.config/monitors.xml and ~/.config/monitors.xml~ but that only got my resolution to reset to the default one AFTER blind login and use of startx

Any suggestions, anyone? Any logs I need to provide you with?

I would like to note an important piece of info: I had my GeForce 6600GT and then upgraded to GeForce 8800GT. IT died after like three weeks, and then I put back my old 6600GT. It worked fine the first day, so I was thinking if it's possible to install OLDER nVidia drivers (like version 220.xx), using the terminal, could that help? And how do I do that?

Thanks in advance!

UPDATE: I managed to try all the driver versions available in "Additional Drivers" but none helped. Still, the only way to access the desktop is via startx and no menus are shown.

3 Answers

This is what helped in the end: I removed lightdm and installed GDM. After reboot, it worked:

• When the HDD stops loading and the black screen appears, type CTRL+ALT+F1
• Type your username and password in the terminal prompt. If you can't even see it, like I couldn't, type your username, press ETNER, then type the password, press ENTER.
• Start XORG by typing startx
• When the desktop appears, open terminal using CTRL+ALT+T
• Remove lightdm using sudo apt-get remove lightdm
• Wait for it to finish, then install GDM using sudo apt-get install gdm
• After it's done, use sudo reboot to restart the computer and GDM should be working

Does anyone know what caused this out of the blue and will I be able to use lightdm again?

did whatever Tesla said but instead of installing GDM simply reinstalled lightdm after removing it:

sudo apt-get install lightdm

This helped solve the problem for me

I had a similar problem after upgrading from 12.04 LTS to 12.10. The system in question happens to be a Virtualbox VM (guest).

What solved the problem for me was to remove all the Virtualbox guest additions, reboot, then re-install the guest additions.

To remove the guest additions from the command line:

sudo apt-get remove virtualbox-guest-additions
sudo apt-get remove virtualbox-guest-dkms
sudo apt-get remove virtualbox-guest-utils
sudo apt-get remove virtualbox-guest-x11

(Don't worry if you don't have some of those installed. However, if you have none of those installed then you don't have the same problem I did.)