Solve display problems in Linux Mint


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Contents of this page:

Major problems (no graphical display at all)

1. You can try to restore normal graphical display in Linux Mint as follows:

a. In the Grub bootloader menu, boot your computer into the advanced options. Select the following line (and press Enter):

Advanced options for Linux Mint 20

b. In the next menu, select the line that ends on: (recovery mode)

c. In the recovery menu that appears then, choose the first option:
resume    Resume normal boot

This will attempt a normal boot with failsafe video settings.

d. No avail? Then restart in recovery mode and choose the fourth option:
failsafeX    Run in failsafe graphic mode

e. No avail again? If you're familiar with the terminal and its commands, then you can restart in recovery mode and choose the option:
root    Drop to root shell prompt

This will allow you to try to restore normal graphical display from the terminal.


Minor problems (bad display)

Other, minor display problems (wrong resolution, unstability, wrong brightness) can have various causes:

Bad stability and performance

2. Stability and performance issues can usually be addressed by disabling the visual effects in Linux Mint (item 5).

Wrong resolution: Nvidia card

3. Do you have an Nvidia card running on the restricted Nvidia driver (which is recommended), and is the display resolution wrong? Then proceed as follows:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Then type in the terminal (use copy/paste):

nvidia-settings

Press Enter.

Now you can configure your display with this nifty tool from Nvidia itself. Proceed as follows:

Click "X Server Display Configuration" (top left, second entry).

Resolution: click the button that says "Auto", and choose the display resolution that you want.

Click Apply. Wish to save the settings? Click "Save to X Configuration File".

Click Quit.

Brightness of the display is wrong and not adjustable

4. Some laptops have a problem with the brightness of the display: the Fn keys to adjust the brightness, don't work. Therefore the brightness of the screen may be too high or too low, which can be maddeningly annoying.

You can try the following progressive scheme:

Easiest method: try the slider

4.1. When you click (Xfce: right-click) on the battery icon in your system tray, you see (among other things) a slider for the brightness. Try if you can set the brightness with that.

If that doesn't help, continue with item 4.2.

Also easy: try the application "light"

4.2. When you're dealing with a laptop display, you might try the application "light". Like this:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Then execute in the terminal (use copy/paste):

sudo apt-get install light

Press Enter. Type your password when required. In Ubuntu this will remain entirely invisible, not even dots will show, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

c. Then in the terminal (use copy/paste):

sudo light -S 50

Press Enter.

(when you type it: the letter S is a capital letter)

This should set the brightness to 50 %. Change the percentage at will (don't go lower than 10 nor higher than 100).

If that doesn't work, continue with item 4.3.

Another easy method to fix the brightness: add a Grub parameter

4.3. It might be sufficient to add a parameter to Grub.

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Then execute in the terminal (use copy/paste):
xed admin:///etc/default/grub

In the text file that opens then, find the line:
GRUB_CMDLINE_LINUX=""

Replace it with this line:
GRUB_CMDLINE_LINUX="acpi_osi=Linux"

Save the file and close it.

c. Now in the terminal:
sudo update-grub

Press Enter. Type your password when required. In Ubuntu this will remain entirely invisible, not even dots will show, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

d. Reboot your computer. The Fn brightness keys should work now. If not, replace the line:
GRUB_CMDLINE_LINUX="acpi_osi=Linux"

by this line:
GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

Then run sudo update-grub again and reboot.

When still no avail, continue with item 4.4 below.

The moderately difficult method to fix the brightness: xbacklight

4.4. By means of xbacklight you might achieve the desired result.

a. First, you install xbacklight:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

sudo apt-get install xbacklight

Press Enter. Type your password when prompted. In Ubuntu this remains entirely invisible, not even dots will show when you type it, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

b. Then create a new startup application:

Query in the menu search box: startup.
Click on Startup Applications.
Click Add

Give the new addition the name Brightness and the command:

xbacklight -set 70

Click Add.

Note: this only takes effect after logging into your user account. If the login window is too dark as well, you might configure your Linux to login automatically.

c. Reboot your computer. The screen brightness should be OK after logging in.

Note: other brightness values than 70 might suit you better; you can experiment with that.

If this doesn't work, try item 4.5 below:

The more difficult method to fix the brightness: setpci

4.5. If all else fails, you might try setpci:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):
lspci | grep -i vga

Press Enter. The output will show the exact type of your video card, and (what's more important right now) the BusID. That's the number with which the output line begins.

The BusID has five digits. Use your digit combination in the terminal command mentioned below (use copy/paste to avoid errors). I'll explain it by means of the following example:

b. When the BusID is 00:02.0, the command to dim an overly bright display is:

sudo setpci -s 00:02.0 F4.B=50

And for this same BusID the command to increase the brightness on a darkish display is:

sudo setpci -s 00:02.0 F4.B=90

Adapt this command according to your BusID.

Press Enter. Type your password when prompted. In Ubuntu this remains entirely invisible, not even dots will show when you type it, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

If all has gone well, this should set the brightness at a better level (in the example: either at 50 or at 90).

c. Experiment with other values in the range of 1 - 100, and pick the one you like best. 100 is maximum.

d. Want to make this permanent? Proceed like this:

e. Create a new file. Type in the terminal (use copy/paste):

sudo touch /etc/rc.local

Press Enter. Type your password when prompted. In Ubuntu this remains entirely invisible, not even dots will show when you type it, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

f. Make the new file executable like this:

sudo chmod +x -v /etc/rc.local

Press Enter.

g. Now open it for editing, like this:

xed admin:///etc/rc.local

Press Enter.

h. Add the following blue text (just an example, use copy/paste to transfer it):

#!/bin/sh -e
setpci -s 00:02.0 F4.B=70
exit 0

i. Save the modified file and close it.

j. Reboot your computer.

k. If no avail, continue with item 4.6.

Last resort: use xrandr for adjusting the brightness

4.6. You can also tune the display brightness with xrandr. That's being done on the software level and not on the hardware level, so it's not the most elegant solution. But sometimes it's the only means left.

First determine the video port to which your display is connected.

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Copy/paste the following command line into the terminal:
xrandr | grep -w connected | cut -f1 -d" "

Press Enter.

On my laptop that generates the following output:
eDP1

That's the video port on my laptop, that's connected to the display.

You can now set the brightness from 0.1 to 1.0. On my laptop this creates a pleasant brightness:
xrandr --output eDP1 --brightness 0.8

Intel graphics: fix a flickering display

5. When you have Intel graphics, you might be plagued by a frequently flickering display, which can be caused by a kernel bug. You may be able to work around that as follows:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Use copy/paste to transfer the following command to the terminal:

xed admin:///etc/default/grub

(the three consecutive slashes are intentional and no typo)

Press Enter. You'll be asked twice for your password, that's normal.

b. Add the following parameter to the line GRUB_CMDLINE_LINUX_DEFAULT:

intel_iommu=off

This is an example of how it should look then (if you have no other custom parameters):

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_iommu=off"

Save the modified document and close it.

c. Then use copy/paste to transfer the following command to the terminal:

sudo update-grub

Press Enter. Type your password when required. In Ubuntu this will remain entirely invisible, not even dots will show, that's normal. In Mint this has changed: you'll see asterisks when you type. Press Enter again.

d. Reboot and test.

Note: this parameter might cause problems when you work with virtual machines, like with VirtualBox and VMware.

Want more tips?

6. Do you want more tips and tweaks? There's a lot more of them on this website!

For example:

Speed up your Linux Mint!

Clean your Linux Mint safely

Avoid 10 fatal mistakes


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