Major problems (no graphical display at all)

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

a. In the Grub bootloader menu, boot your computer into recovery mode:

Ubuntu:
Advanced options for Ubuntu – Ubuntu, with Linux xxxxxxx (recovery mode)

Press Enter.

b. 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.

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

d. 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, instability, wrong brightness) can have various causes:

Bad stability and performance

2. Stability and performance issues can usually be addressed by disabling the visual effects (switching to another desktop environment).

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. First make sure that you have installed the application gksu:

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

Type (or copy/paste):
sudo apt-get install gksu

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

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

On the right in the window: click the tab “Display” (which should be opened already).

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

Click “Save to X Configuration File”.

Click Close.

c. Reboot your computer. Now the display resolution should be right.

Wrong resolution: SiS 671/771 card

4. For the SiS 671/771 video card, check here.

Wrong resolution: XGI Z7 or Z9 card

5. For the XGI Z7 or Z9 video card, look here.

Brightness of the display is wrong and not adjustable

6. 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.

In some cases this can be solved by installing Brightness Applet in the panel. With that, you can try to adjust the brightness. But sometimes even that doesn’t work. Then you can try the following progressive scheme:

Easy method: fix brightness for an Intel video card

6.1. For an Intel video card you can do the following to fix the brightness:

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

b. Copy/paste this command into the terminal:
ls /sys/class/backlight/

Press Enter. You have an Intel video card when the output reads:
intel_backlight

c. Copy/paste the following command line into the terminal:
sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

Press Enter. When prompted, type your password. This will remain entirely invisible, you won’t even see dots, this is normal. With this command you create an empty text file.

d. Now make sure that you have installed the applications gksu and leafpad:

Copy/paste into the terminal:
sudo apt-get install gksu leafpad

Press Enter.

e. Now copy/paste this line into the terminal:
gksudo leafpad /usr/share/X11/xorg.conf.d/20-intel.conf

Press Enter.

Copy/paste the following text block into that empty text file:

Section “Device”
Identifier “card0”
Driver “intel”
Option “Backlight” “intel_backlight”
BusID “PCI:0:2:0”

EndSection

Save the modified text file and close it.

f. Reboot your computer: you should be able to change the display brightness now, with the usual Fn keys. If not, continue with item 6.2 in the right column of this page.

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

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

a. First make sure that you have installed the applications gksu and leafpad:

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

Type (or copy/paste):
sudo apt-get install gksu leafpad

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

b. Then type in the terminal (use copy/paste):
gksudo leafpad /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; this will remain entirely invisible, not even dots will show, this is normal. Press Enter again.

d. Reboot your computer. The Fn brightness keys should work now. If not, continue with 6.3.

The moderately difficult method to fix the brightness: xbacklight

6.3. 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. When prompted, type your password. Your password will remain entirely invisible, not even dots will show, this is normal.
Press Enter again.

b. Then create a new startup application.

Ubuntu: click on the grey Ubuntu logo (Dash home). Query: 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 Ubuntu 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 6.4:

The more difficult method to fix the brightness: setpci

6.4. 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; this remains entirely invisible, not even dots will show, this is normal. 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).

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

c. You can make this setting permanent, so that it’ll survive a reboot. Like this:

– First make sure that you have installed the applications gksu and leafpad:

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

Type in the terminal (use copy/paste):
sudo apt-get install gksu leafpad

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

– Then type in the terminal (use copy/paste):
gksudo leafpad /etc/rc.local

Press Enter.

Now Leafpad opens with a text file. Add the following line (use copy/paste to avoid errors), just above the existing line exit 0:
setpci -s 00:02.0 F4.B=50

(adapt this line to your BusID and desired brightness level)

It will become like this then (example):

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will “exit 0” on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
setpci -s 00:02.0 F4.B=50
exit 0

Save and close the modified file.

d. Reboot your computer. The brightness should be alright now. If not, continue with 6.5.

Last resort: use xrandr for adjusting the brightness

6.5. 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 connected | cut -f1 -d” ”

Press Enter.

On my laptop that generates the following output:
LVDS1
VGA1
HDMI1
DP1
VIRTUAL1

Those are all the available video ports on my laptop.

You can now set the brightness from 0.1 to 1.0. On my laptop this creates a pleasant brightness:
xrandr –output LVDS1 –brightness 0.8

On my laptop the display is connected to the first port, so LVDS1. For your computer that could be different; use trial and error to find out…. When you specify the wrong port, you get this error message:
xrandr: Need crtc to set gamma on.