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Thread: Screen brightness set to zero at each bootup of 13.10-64 on a HP Pavilion dv4 Noteboo

  1. #1
    Join Date
    Dec 2008
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    W-slp-Sierra Nevada usa
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    1,391
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    Ubuntu 14.04 Trusty Tahr

    Screen brightness set to zero at each bootup of 13.10-64 on a HP Pavilion dv4 Noteboo

    New complete installation of 13.10-64 Desktop release on a HP Pavilion dv4 Notebook PC (WA684UA#ABA). During boot, the purple Ubuntu screen shows for a moment, then goes black. Machine boots up correctly, but the screen brightness must be turned up (alt-F8) before anything can be seen. Once brightened, it runs fine until the next boot cycle. Same scenario then repeats. No additional drivers being used.

    How to fix??

    Thanks,

    After searching around I may have found a fix for this:

    https://bugs.launchpad.net/ubuntu/+s...er/+bug/968532

    Post #2: says; I found this workaround (from bug #35223, comment #51):"[...] If I put
    echo 2 > /sys/class/backlight/acpi_video0/brightness
    in /etc/rc.local (before exit 0) it seems to work."
    Indeed it works; I just changed 2 to 1, as 1 gives a low but acceptable brightness level on this lapto

    After testing it I will mark solved if it works.

    --------------------0---------------------------

    I have tested and the results are good.

    Yes, that does work for me, and of course it "sticks", since it is a change to etc/rc.local.
    echo 2 I've changed to echo 20, which sets brightness to 100% it appears, what kind of number base is that????????

    marking this solved.
    Last edited by Hakunka-Matata; December 22nd, 2013 at 07:04 AM.
    boot_info_script by meierfra & Gert Hulselmans
    unetbootin to burn liveCD/USB
    Repair Windows7 Boot
    Partitioning

  2. #2
    Join Date
    Nov 2010
    Location
    India
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    4,821
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    Ubuntu Development Release

    Re: Screen brightness set to zero at each bootup of 13.10-64 on a HP Pavilion dv4 Not

    have you tried any of these commands ?

    http://askubuntu.com/questions/14905.../149265#149265
    Raja

    రాజ శేఖర్ రెడ్డి

  3. #3
    Join Date
    Dec 2008
    Location
    W-slp-Sierra Nevada usa
    Beans
    1,391
    Distro
    Ubuntu 14.04 Trusty Tahr

    Re: Screen brightness set to zero at each bootup of 13.10-64 on a HP Pavilion dv4 Not

    Thank you raja, as you will notice in my original post (edited), it's fixed.
    Last edited by Hakunka-Matata; December 22nd, 2013 at 05:22 PM.
    boot_info_script by meierfra & Gert Hulselmans
    unetbootin to burn liveCD/USB
    Repair Windows7 Boot
    Partitioning

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