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Thread: Powerbook brightness adjustment problems

  1. #1
    Join Date
    Apr 2008

    Powerbook brightness adjustment problems

    I just installed Hardy on my 1.5 Ghz powerbook, and it seems to work pretty well, with a few issues. The main problem is the brightness adjustment keys - when I press F1/F2, the brightness indicator pops up, but it always displays zero brightness, and the screen stays at full brightness.

    I also have a somewhat similar issue with the volume keys, but it's just cosmetic - the volume changes, but the volume level displayed onscreen is sometimes the actual volume, and sometimes zero.

    The backlit keyboard doesn't work either, but I don't particularly care about that.

  2. #2
    Join Date
    Dec 2006
    Hardy Heron (Ubuntu Development)

    Re: Powerbook brightness adjustment problems

    Do you have the package pommed installed?
    Macbook Pro C2D
    Ubuntu 8.04

  3. #3
    Join Date
    Apr 2008

    Re: Powerbook brightness adjustment problems

    Sorry it's taken me so long to respond to this... I've installed pommed, but it doesn't appear to be starting. If I run "sudo pommed -d", I get:

    mwoenker@mwoenker-laptop:~$ sudo pommed -d
    I: pommed v1.15 ($Rev: 434 $) Apple laptops hotkeys handler
    I: Copyright (C) 2006-2008 Julien BLACHE <>
    pommed configuration:
     + General settings:
        fnmode: 1
     + sysfs backlight control:
        initial level: -1
        step: 8
        on_batt: 40
     + Audio volume control:
        card: default
        initial volume: -1
        step: 10%
        beep: yes
        volume element: Master
        speaker element: Master
        headphones element: Headphone
     + Keyboard backlight control:
        default level: 100
        step: 16
        auto on threshold: 20
        auto off threshold: 40
        auto enable: yes
        idle timer: 60s
     + CD eject:
        enabled: yes
        device: /dev/dvd
     + Beep:
        enabled: no
        beepfile: /usr/share/pommed/goutte.wav
    device-tree copyright node: [Copyright 1983-2004 Apple Computer, Inc. All Rights Reserved]
    device-tree model node: [PowerBook5,4]
    I: PMU machine check: running on a PowerBook5,4
    Failed to access brightness node: No such file or directory
    E: LCD backlight probe failed, check debug output

  4. #4
    Join Date
    May 2008
    Ubuntu 11.04 Natty Narwhal
    Same problem here on my PB G4... =(

  5. #5
    Join Date
    Oct 2008

    Re: Powerbook brightness adjustment problems

    Has there been any fixes for this yet? I am having the same problem and would like to see it fixed.

  6. #6
    Join Date
    Jan 2006

    Re: Powerbook brightness adjustment problems

    How about pbuttonsd?

    There is a quick fix in the wiki about half way through:

    Although this has been a sticky problem for ages - the guys in cupertino just won't let go of the hardware specs for the Linux devs to work on.

    You can mitigate it somewhat by messing around with gamma, or using a dark theme, although the background in firefox is always white-hot.

    xgamma -gamma 0.5
    The usable range is from about 0.5 to 1.5, with 1 being the default. Of course this changes your gamma, so I wouldn't go editing critical photos with this kind of change. When you find a setting you like, you can make it permanent in your xorg.conf file.

    Xubuntu (and XFCE in other distros) has two great gamma controls. One will adjust the red, blue, and green gamma separately, while there is also an overall brightness adjustment which may help.

    These aren't as good as a dedicated hardware brightness controls, but may serve to make the system usable. Although using xgamma techniques might not save you much battery power.

    You can also try using a very dark them, such as "darkroom", which I've seen in Intrepid and make other tweaks to darken everything.

    This might enable you to at least live with the system until a hardware fix is applied or found.
    20" G5 iMac - AMD64 HP desktop

  7. #7
    Join Date
    Mar 2008
    Ubuntu Development Release

    Re: Powerbook brightness adjustment problems

    I know this thread is quite old, but this might be of help to some:

    I've had the same problem on my brothers PowerBook G4 (Geforce 4 Go 440) and Ubuntu Jaunty. My "fix" was to ditch the included kernel and compile a custom kernel specifically designed to work with just that machine (and leaving out all the junk it doesn't make sense using - like DVB cards). Now I can control the brightness with the F1/F2-keys, the bootsplash shows the real colours now and a few minor things are also fixed. If anyones interested, I can supply you with the corresponding config-file for the 2.6.29-series.
    Last edited by moviemaniac; May 22nd, 2009 at 10:43 AM.
    My machines:
    iMac 24" (8,1): Ubuntu 11.04 | Lenovo S12: Ubuntu 11.04

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  8. #8
    Join Date
    Sep 2007
    Brooklyn, NY

    Re: Powerbook brightness adjustment problems

    I have an old PowerBook G4 that I wanted to bring back to lfie. I've installed 10.10 without any problems, but the first bug I found was the brightness hotkeys not working. I've installed both pommed and pbbuttonsd and still nothing. The volume keys work fine, it's just the brightness keys. Anyone know of any simple fixes? Thanks.

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