How to access the command line on CentOS 7 when encountering a black screen?

If you encounter a black screen and can’t enter the graphical interface on CentOS 7, you can try the following method to enter command-line mode:

1. Press the combination of Ctrl + Alt + F2 (or F3, F4, F5, F6). This will switch to virtual console 2 (or other virtual console) to enter command line mode.
2. If pressing Ctrl + Alt + F2 does not work, you can try pressing Ctrl + Alt + Delete, then wait for the system to restart. During the restart process, pressing Ctrl + Alt + F2 will allow you to enter command line mode.
3. If the above methods are ineffective, you can try entering command-line mode using recovery mode. Start the computer and select “Advanced options for CentOS 7” in the GRUB boot menu, then choose a kernel version that includes “recovery mode” or “rescue mode”. Once in recovery mode, select “Drop to root shell prompt” or a similar option to access the command-line mode.

Once you have successfully entered the command line mode, you can attempt to fix graphical interface related issues, such as reinstalling or updating graphics card drivers, checking Xorg configuration files, and so on, using any method available.