I'm using an IBM Thinkpad X21 as a 3G router. It's running a server install of lucid. The laptop has the lid up most of the time. There is no X, just a plain console. The colsole blanks itself, but the LCD backlight is always on.

The graphics chip is ATI Technologies Inc Rage Mobility P/M AGP 2x (rev 64).

The following modules related to the framebuffer are now loaded:

$ lsmod | grep fb
fbcon                  35102  71 
tileblit                2031  1 fbcon
font                    7557  1 fbcon
bitblit                 4707  1 fbcon
vga16fb                11385  1 
vgastate                8961  1 vga16fb

Can I make the LCD backlight turn off when the colsole is unused and have it turn on automatically when needed?


You should be able to use setterm to do this:

# turn power save on, blank after 10 mins, powerdown after 20mins
setterm -powersave on -blank 10 -powerdown 20
  • Looks to be a better solution than my answer. – user987 Aug 9 '10 at 1:44
  • This does not change the backlight at all. VESA power management does not appear to work on laptop screens. Even if it did, you could have mentioned which config file contains the setterm settings that are applied on boot. The router laptop is more often rebooted that logged in into. – Albertas Agejevas Aug 11 '10 at 15:55

vbetool works for me. I have used it on a dell inspiron 8100. Old computer, but it is supposed to be a general tool, I believe.

It was not installed by default on my computer: Ubuntu server 9.04.

I installed it using apt-get:

sudo apt-get install vbetool

Then, I can execute it:

sudo vbetool dpms off
sudo vbetool dpms on

For me this turns the laptop monitor completely off (including the backlight) and then on.

Doesn't seem to be exactly what you want, but maybe it is close enough.

Hope this helps

  • This is an old answer but this is working pretty fine on Ubuntu 20.04 today. The only problem is that once you try to turn the screen on, the video is distorted. Any ideas on how to fix this? Thank you very much. – Geppettvs D'Constanzo Jul 29 '20 at 20:12

Not quite as automatically as you might like, still issuing the following ought to turn the brightness all the way down. Further poking around in the /sys tree might reveal other complementary steps to improve on it:

sudo su -c 'echo "0" > /sys/devices/virtual/backlight/acpi_video0/brightness';

Then use the power buttons on the keyboard to get the brightness back up. Be sure to verify the correctness of this line w.r.t. how your /sys tree looks.

  • Even on a modern laptop, it makes the brightness just dimmer. On the X21 the file name is /sys/devices/virtual/backlight/thinkpad_screen/brightness, and writing to it does not change the backlight at all. – Albertas Agejevas Aug 11 '10 at 15:51

Not the answer you're looking for? Browse other questions tagged or ask your own question.