Display / Screen Issues

Screen looks wrong, stuck at low resolution, tearing, or black screen after login? This guide covers the most common display problems on Linux and how to fix them.

Screen Resolution Wrong or Stuck at Low Res

If your screen is stuck at something like 1024x768 or 800x600 when it should be much higher, it's almost always a graphics driver issue. Your system is using a generic fallback driver instead of the proper one for your GPU.

Check what driver you're using

# See what GPU you have
lspci | grep -i vga

# Check which driver is loaded
lsmod | grep -E 'nvidia|amdgpu|i915|nouveau'

# See available resolutions
xrandr   # On X11
# On Wayland, check your desktop's display settings instead

Fix it based on your GPU

• NVIDIA: You probably need the proprietary NVIDIA driver. The open-source nouveau driver often doesn't support higher resolutions properly. See our NVIDIA driver guide for step-by-step instructions.
• AMD: The open-source amdgpu driver works great and is usually loaded automatically. If it's not, make sure you have xf86-video-amdgpu (Arch) or xserver-xorg-video-amdgpu (Ubuntu/Debian) installed.
• Intel: Intel integrated graphics use the i915 driver, which is built into the kernel. If it's not working, try updating your kernel.

Screen Tearing

Screen tearing looks like a horizontal line cutting across your screen where the top and bottom halves are slightly out of sync. It's especially noticeable when scrolling or watching video. It happens when your display is updating in the middle of a frame being drawn.

The fix depends on your desktop environment:

# Force full composition pipeline (NVIDIA on X11)
sudo nvidia-settings --assign CurrentMetaMode="nvidia-auto-select +0+0 { ForceFullCompositionPipeline = On }"

# To make it permanent, add it to your xorg config:
# See our NVIDIA guide for details

# Install picom
# Ubuntu/Debian: sudo apt install picom
# Fedora: sudo dnf install picom
# Arch: sudo pacman -S picom

# Disable XFCE compositor, then start picom
picom --vsync &

Multi-Monitor Setup

Linux handles multiple monitors well these days, but getting everything arranged correctly takes a little setup.

Arranging displays

• GNOME: Open Settings → Displays. Drag the monitor rectangles to match your physical layout. Click Apply.
• KDE: Open System Settings → Display and Monitor → Display Configuration. Drag monitors into position and click Apply.

Different refresh rates

If you have a 144Hz gaming monitor and a 60Hz secondary display, you might notice the 144Hz monitor stuttering when both are active. This used to be a big problem, but the situation has improved:

• Wayland: Handles mixed refresh rates natively. Each monitor runs at its own refresh rate independently. This is one of the big advantages of Wayland over X11.
• X11: All monitors are synced to the same VSync, which can cause stuttering. If your desktop supports it, switch to Wayland for a better experience.

Per-monitor scaling

If one monitor is 4K and the other is 1080p, you'll want different scaling on each:

• GNOME on Wayland: Supports per-monitor scaling natively. Open Settings → Displays, select each monitor, and set its scale independently.
• KDE on Wayland: Also supports per-monitor scaling. Open System Settings → Display and Monitor, click each monitor, and adjust the scale.
• X11: Per-monitor scaling is not well supported. You'll usually need to set one global scale and then use xrandr --output <name> --scale to adjust individual monitors, which can cause blurriness.

HiDPI / 4K Scaling

If you have a high-resolution display (4K, 5K, or a high-DPI laptop screen), everything might look tiny by default. You need to enable scaling so text, icons, and windows are a usable size.

GNOME

GNOME supports integer scaling (100%, 200%) out of the box. For fractional scaling (125%, 150%, 175%):

# Enable fractional scaling on Wayland
gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"

# Then go to Settings → Displays and you'll see more scale options

KDE Plasma

KDE has built-in fractional scaling support:

1. Open System Settings → Display and Monitor
2. Select your display and adjust the Scale slider (you can set any value like 125%, 150%, etc.)
3. Click Apply and log out/in for the best results

Per-app issues

Even with system-wide scaling set correctly, some apps might look blurry or the wrong size:

• Electron apps (VS Code, Discord, Slack): Add --force-device-scale-factor=1.5 to the launch command (replace 1.5 with your scale). You can also set the ELECTRON_SCALE_FACTOR environment variable.
• Older GTK2 apps: These don't understand scaling. Not much you can do besides using the app's built-in zoom if it has one.
• Java apps: Set GDK_SCALE=2 or use -Dsun.java2d.uiScale=2 as a JVM argument.
• Firefox: Go to about:config and set layout.css.devPixelsPerPx to your desired scale (e.g., 1.5).
• XWayland apps: Apps running through XWayland on a Wayland session may look blurry at fractional scales. GNOME renders them at a higher resolution and scales down, which helps. KDE is improving this as well.

Black Screen After Login

You type your password, the screen goes black, and nothing happens. You might see a cursor, or the screen might be completely dark. This is one of the scariest issues, but it's usually fixable.

Common causes

• Wrong GPU driver: Especially common with NVIDIA. If you installed (or uninstalled) the NVIDIA driver and something went wrong, you can end up with a black screen. See our NVIDIA guide.
• Display manager crashed: The login screen program (GDM, SDDM, LightDM) itself might have crashed.
• Desktop environment crashed: You logged in fine, but GNOME/KDE/etc. failed to start.

How to recover

# 1. Switch to a text console (this works even with a black screen)
#    Press Ctrl + Alt + F2 (or F3, F4, F5, F6)
#    Log in with your username and password

# 2. Check the display manager status
sudo systemctl status gdm      # GNOME
sudo systemctl status sddm     # KDE
sudo systemctl status lightdm  # XFCE / others

# 3. Check for GPU driver issues
lsmod | grep -E 'nvidia|nouveau|amdgpu'
dmesg | grep -i -E 'gpu|drm|nvidia|error'

# 4. Try restarting the display manager
sudo systemctl restart gdm     # Or sddm / lightdm

# 5. If it's an NVIDIA issue, you can try switching to the open-source driver
sudo apt remove nvidia-driver-*   # Ubuntu/Debian
sudo reboot
# Then reinstall the correct driver after rebooting

Flickering Screen

A flickering display can range from a subtle flicker to the whole screen rapidly turning on and off. Here's what to check:

Wayland vs X11 differences

• On Wayland: Flickering is less common but can happen with NVIDIA GPUs (especially with older driver versions). Make sure you're running NVIDIA driver 545 or newer for the best Wayland experience.
• On X11: Flickering is often caused by compositor issues. Try disabling and re-enabling the compositor, or switching between compositors.

General fixes

# Check for GPU errors in the kernel log
dmesg | grep -i -E 'drm|gpu|display|flicker'

# On X11, try disabling the compositor temporarily
# KDE: Alt + Shift + F12 toggles the compositor
# XFCE: Settings → Window Manager Tweaks → Compositor → uncheck "Enable"

# If flickering happens with an NVIDIA GPU, try adding this kernel parameter:
# nvidia-drm.modeset=1
# Edit /etc/default/grub and add it to GRUB_CMDLINE_LINUX_DEFAULT
sudo update-grub   # Ubuntu/Debian
sudo grub2-mkconfig -o /boot/grub2/grub.cfg   # Fedora

External Monitor Not Detected

You plug in an external monitor and nothing happens. Here's how to troubleshoot:

Check the basics first

• Try a different cable. HDMI and DisplayPort cables can be flaky. If you have another one, test with that.
• Try a different port. If your laptop has multiple video outputs, try another one.
• Check the monitor's input setting. Make sure the monitor is set to the right input (HDMI 1 vs HDMI 2, etc.).

On X11

# List all connected and disconnected outputs
xrandr

# If the monitor shows as "connected" but no image:
xrandr --output HDMI-1 --auto

# If it shows as "disconnected" even though it's plugged in:
# Force detection
xrandr --output HDMI-1 --mode 1920x1080

# If your resolution isn't listed, you can add it manually:
cvt 1920 1080 60   # Generate modeline for your resolution
# Copy the modeline output, then:
xrandr --newmode "1920x1080_60" [paste modeline values here]
xrandr --addmode HDMI-1 "1920x1080_60"
xrandr --output HDMI-1 --mode "1920x1080_60"

On Wayland

Wayland doesn't use xrandr. Instead, your desktop environment handles display detection:

• GNOME: Open Settings → Displays. If the monitor appears here, you can configure it. If not, the issue is at the hardware/driver level.
• KDE: Open System Settings → Display and Monitor. Same idea -- if it shows up, configure it here.
• You can check if the kernel sees the monitor with: cat /sys/class/drm/*/status -- look for "connected" entries.

# Edit your GRUB config
sudo nano /etc/default/grub

# Find the line that starts with GRUB_CMDLINE_LINUX_DEFAULT
# Add one of these options (try them one at a time):

# Option 1 (most common fix):
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

# Option 2:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=native"

# Option 3 (for newer kernels):
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=video"

# Save the file, then update GRUB:
sudo update-grub   # Ubuntu/Debian/Mint
sudo grub2-mkconfig -o /boot/grub2/grub.cfg   # Fedora

# Find your backlight device
ls /sys/class/backlight/

# Check current and max brightness
cat /sys/class/backlight/*/brightness
cat /sys/class/backlight/*/max_brightness

# Set brightness manually (replace intel_backlight with your device)
# Value is between 0 and max_brightness
echo 500 | sudo tee /sys/class/backlight/intel_backlight/brightness

# brightnessctl is a handy command-line tool
# Ubuntu/Debian: sudo apt install brightnessctl
# Fedora: sudo dnf install brightnessctl
# Arch: sudo pacman -S brightnessctl

# Set brightness to 50%
brightnessctl set 50%

# Increase by 10%
brightnessctl set +10%

# Decrease by 10%
brightnessctl set 10%-

Night Light / Blue Light Filter

Staring at a bright blue screen at night can make it harder to sleep. Both major desktops have a built-in night light feature that warms the screen color in the evening.

GNOME

1. Open Settings → Displays → Night Light
2. Toggle it on
3. Set a schedule (Sunset to Sunrise is the easiest -- it uses your location automatically) or set manual times
4. Adjust the Color Temperature slider to your preference

KDE Plasma

1. Open System Settings → Display and Monitor → Night Light (called "Night Color" in older versions)
2. Enable it and choose a schedule
3. Adjust the color temperature

Other desktops or manual setup

If your desktop doesn't have a built-in night light, you can use redshift or gammastep (Wayland-compatible):

# Install redshift (X11) or gammastep (Wayland)
# Ubuntu/Debian:
sudo apt install redshift    # X11
sudo apt install gammastep   # Wayland

# Run it (adjusts automatically based on time of day)
redshift          # X11
gammastep         # Wayland

# Or set a specific color temperature (lower = warmer)
redshift -O 4500
gammastep -O 4500

# Check your current session type
echo $XDG_SESSION_TYPE
# Prints "wayland" or "x11"