Black screen instead of login screen

Question

I'm having a serious problem. I use dual OS, so I'm posting with Windows. Somewhat about 2-3 hours before everything was working fine I have modified Ubuntu a lot and was using Mac OS X login screen. It was working fine but I was just having fun and typed this command in terminal to power off (using Ubuntu 13.10) {and using root}.

sudo shutdown -h now

Also I changed the password for su using

sudo passwd root

I kept my laptop aside and came after 2-3 hours. it booted with a splash screen of mac. then it took to a blank screen (OK this happens every time, but after 5-10 seconds login appears), but these times I'm getting a black screen with a mouse. I can move the mouse but can't log in. Only the black screen is there, but everything else is working when I press power button it shuts down like usual.

I'm stuck, please help me!

Solution 1

To fix this, follow the steps below:

1- Turn on your computer and wait for it to boot up.

2- Once it boots up, press Ctrl+Alt+F1 to enter terminal

3- Type your username, press enter, and type your password and press enter again.

4- Now type

startx

This should start your desktop. Once here, you can uninstall/reset whatever was causing the problem (in this case Mac OS LightDM theme).

5- Reboot the computer it should boot up normally!

Solution 2

Try to run the following command:

sudo apt-get install lightdm --reinstall

and restart, if it works then enjoy.

If it does not work, then you can run following command:

sudo deborphan | sudo xargs apt-get -y remove lightdm --purge && sudo apt-get install lightdm

Comments

[tr33hous]

what happens when you try to access the virtual shells (Ctrl+Alt+F1, Ctrl+Alt+F2 etc.)

[Ukiyo]

it said pcname login:dont know what to type and password : in next line

[Ukiyo]

but i dont know my user name altough i know my acc name .is my user name that one which come sin terminal ****@pcname :

[Moose]

Try logging into root. Un:root. PW:(what you set it as). Then type 'CD /home' then type 'ls'. What does that output?

[Ukiyo]

im using this login github.com/Wattos/LightDM-Webkit-MacOSX-Theme

[Moose]

Sorry.. Your username is what you said in the first comment

[Ukiyo]

ok let me try rebooting my pc so will take some time to post btw what to type here Un:root. PW:(what you set it as !!!here!!)

[Moose]

You can either log in as root (un:root, pw:(what you set it as when you type sudo passwd root)), or as your normal user. (un:acount name, pw:your normal password.

[Ukiyo]

Ok I logged in with my acc and did cd and ls it is showing names of files on desktop like normal terminal

[Ukiyo]

No same login black didnt work

[Ukiyo]

Unity panel service no processes found ; compiz core - fatal : couldn't open display; stopping plugin core unloading plugin core

[Moose]

First of all, you might want to back up important data, just in case... But then you can type sudo 'apt-get purge lightdm,' then when that completes, type 'sudo apt-get install lightdm' This should re-install the login.

[Moose]

Note: this is copied from: bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1066410

[Ukiyo]

i did sudo startx and desktop opened and i changed settings

[Moose]

Try rebooting, does it still work?

[Ukiyo]

it worked! actually what i did was i changed my greeter in lightdm.conf after using sudo starx. and restarted now it is default login screen.

[Ukiyo]

thx for help but i resolved

[Ukiyo]

btw thx for your help friend

[Rmano]

DeveloperNewb or @AshwinSekhari: please one of you edit this answer so that it contains the correct solution; think about making this useful for others; as well as you are advised to delete the personal comments here to clean the Q/A up. Thanks!

[Ukiyo]

removed my useless comments