Symptoms
- GRUB menu appears but screen goes black after
- Cursor blinks on an empty screen
- Login screen never appears
- Worked before a recent update or driver install
Likely causes
- CommonGraphics driver conflict after an updateA new kernel or driver update can be incompatible with your graphics hardware.
- CommonDisplay manager (login screen) crashedThe service that shows the graphical login can fail to start.
- PossibleWrong display output selectedThe system may be sending video to a different port than the monitor is plugged into.
- Less commonCorrupted filesystem or failing driveBoot can hang if the system can't read critical files reliably.
What to do
- At the GRUB menu, select an older kernel version under Advanced options and see if it boots normally.
- If that works, the newest kernel or driver update is likely the cause; hold that package back until a fix is released.
- From GRUB, try Recovery Mode, then choose 'resume' or drop to a root shell to investigate.
- In recovery or a terminal (Ctrl+Alt+F2 for a text console), run 'sudo systemctl restart gdm' (or lightdm/sddm depending on your setup) to restart the login screen.
- If the screen is truly black with no cursor, try adding 'nomodeset' to the boot line in GRUB to bypass the graphics driver temporarily.
- Once logged in via a text console, run a full update: 'sudo apt update && sudo apt full-upgrade' to get compatible drivers.
- If the drive itself is suspect, boot from a USB live disk and run 'fsck' or check SMART status before reinstalling.
Tools and parts
- USB drive with a Linux live image (for recovery)
- Another computer to prepare the USB
When to call a pro
If you're not comfortable with a text-only terminal or the drive seems to be failing, a Linux-savvy technician can recover data and reinstall.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.