Black screen of ubuntu 12.04 system, black screen of login interface

Ubuntu 12.04 system black screen, logon interface black screen 1. hardware environment Intel®Core™I5-2400 CPU @ 3.10 GHz x 4 2. graphics card Intel integrated graphics card 3. the system version is ubuntu12.04.2 4. after the system is turned on, you can see the grub menu. Go to ubuntu 12.04 through the grub menu. The screen turns black and the cursor keeps flashing in the upper left corner. 5. The graphic interface program is damaged. It may be because xorg-related files are cleared when the kernel is updated or the software is installed. 6. solution. After the black screen is displayed, Ctrl + ALT + F4 enters the command line mode. sudo apt-get update sudo apt-get install xserver-xorg-lts-quantal sudo dpkg-reconfigure xserver-xorg-lts-quantal sudo reboot