January 8, 2009

Turn off LCD Display Backlight from Linux command line

Use vbetool to turn off the backlight in an LCD display from the Linux command line. This is useful if using Linux on a laptop computer in text mode. The normal screen blanking utilities do not turn off the backlight, leaving a dull glow and using power unnecessarily. The vbetool utility can manipulate the VESA DPMS (Display Power Management Signaling) features of the display. DPMS can turn off the backlight. Use vbetool dpms off to turn it off, vbetool dpms on to turn it on.

This is not a screensaver, the display will not turn back on by using the keyboard, it has to be turned back on with vbetool or reboot the computer. Remotely accessing the computer with ssh can be used to turn the display on or blind typing on the console can be used. The vbetool command could be put in a startup script like rc.local to boot with the display off.

This was tested on a Toshiba Satellite 2455 Series laptop running CentOS. Power consumption dropped from 30W to 20W.

13 comments:

  1. Thanks a lot, I have a notebook server and it was quite annoying that it still has backlight on even if it has closed lid.

    Cheeers

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  2. Tested on Acer Extensa 5200 with Ubuntu and also on dell d600 ubuntu server. Both works well. If you combine it with ACPI - /etc/acpi/event/lid, you can turn off lid in closed state and turn on when opened.

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  3. Thank you, thank you , thank you!! I've been looking everywhere for a command that worked with my ubuntu photo frame.

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  4. Wonderful. Just got a new Dell Inspiron 1521 and my previous notebook had screen managed in BIOS so never thought this would need taking care of... Anw, brilliant sollution.

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  5. At last found! Thanks a lot! Exactly what I've needed.

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  6. works on a 20 inch iMac

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  7. Thanks a bunch.
    Works fine with Dell Latitude C600 Arch Linux server.

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  8. Thank you - this worked perfectly with my MSI Wind running Ubuntu 10.04 Server.

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  9. Worked perfectly on my Compaq Evo N600c under Debian stable. Thanks!

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  10. Looks great, but where do I get the tool? Thanks!

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  11. Ok, got it, but how do I install it?

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  12. Works fine with 11.10 on HP Omnibook 6000

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  13. Work with HP Omnibook 6000 (Debian)

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