I have an acer aspire 5745dg laptop and i have also a very serious problem!!

My brightness is always at maximun and I cannot change it with the fn keys or from the power management and my battery discharging fast:/.

Thats my problem and i need your help guys!!!!In my windows partition brightness works perfectly only in ubuntu I have this serious and annoying problem!!!!Please reply to my message i'd appreciate that!

  • 2
    Hi, welcome to AU. Can you change the brightness from the "Screen" setting application? Search "bright" in the dash.
    – Jjed
    Apr 27, 2012 at 0:35
  • This question appears to be abandoned, if you are experiencing a similar issue please ask a new question with details pertaining to your problem. If you feel this question is not abandoned, please flag the question explaining that. :)
    – Seth
    Dec 26, 2012 at 0:47

2 Answers 2


I also own a Acer netbook. I use

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

where XX is your brightness level.

XX = FF for max brightness
XX = 30 my setting
XX = 00 no brightness

Try this:


  1. Open the grub configuration file.

     gksudo gedit /etc/default/grub
  2. Find this line GRUB_CMDLINE_LINUX="" and change it to:

  3. Save the file and close the text editor.

  4. Update Grub.

     sudo update-grub
  5. Restart your computer and try to change the brightness.

Similar Question

"Can't Adjust Brightness on My Laptop"

  • i tried it but nothnig happened anything else?:/ Apr 26, 2012 at 20:48
  • I would look at the link I posted labeled "Can't adjust brightness on my laptop" and try the other things there. They had an Acer too.
    – jamesadney
    Apr 26, 2012 at 21:10

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