The Notebook Review forums were hosted by TechTarget, who shut down them down on January 31, 2022. This static read-only archive was pulled by NBR forum users between January 20 and January 31, 2022, in an effort to make sure that the valuable technical information that had been posted on the forums is preserved. For current discussions, many NBR forum users moved over to NotebookTalk.net after the shutdown.
Problems? See this thread at archive.org.

    The Weirdest Problem !!!

    Discussion in 'Lenovo' started by TechOutsider, Dec 10, 2011.

  1. TechOutsider

    TechOutsider Notebook Enthusiast

    Reputations:
    0
    Messages:
    18
    Likes Received:
    0
    Trophy Points:
    5
    I have a very odd problem with my Lenovo B575, which is about 2-3 months old. The screen brightness fluctuates when I'm browsing the web!!

    The weirder thing is that the screen brightness seems to change with the website. E.g. if I visit a predominately dark website such as dpreview.com the screen brightness will decrease. But when I hit CTRL + T to open a new, blank, white, tab, the screen brightness will increase dramatically!

    And no, I'm not on drugs! I never notice such a phenomenon on my desktop :eek:!

    And no, my computer does not have an ambient light sensor or anything like that. And no, it's not a software issue. I've noticed this problem on Chrome and IE, Windows 7 and Windows 8.

    I'm going to take a picture of it as soon as I find my camera! In the mean time, does anyone experience the same thing?
     
    TechOutsider, Dec 10, 2011
    #1
  2. Thors.Hammer

    Thors.Hammer Notebook Enthusiast

    Reputations:
    982
    Messages:
    5,162
    Likes Received:
    33
    Trophy Points:
    216
    Does this happen mostly on sites using Flash? Are you on battery power when this happens?
     
    Thors.Hammer, Dec 10, 2011
    #2
  3. MidnightSun

    MidnightSun Emodicon

    Reputations:
    6,668
    Messages:
    8,224
    Likes Received:
    231
    Trophy Points:
    231
    Funnily enough, this is actually a built-in AMD power-saving scheme called " VariBright," and it is a software issue. VariBright doesn't work so well in reality, so I have it disabled on my Thinkpad X120e, which runs the same E-350 platform as your B575.

    Here's how to disable Varibright: open up AMD Vision Engine Control Center from the Start Menu. In the main screen, under Power, click on PowerPlay. Then, uncheck "Enable Vari-Bright." Now, there shouldn't be any random display brightness changes.

    Note that you will have to re-disable this setting every time you update your AMD drivers.
     
    MidnightSun, Dec 10, 2011
    #3
  4. TechOutsider

    TechOutsider Notebook Enthusiast

    Reputations:
    0
    Messages:
    18
    Likes Received:
    0
    Trophy Points:
    5
    Thanks for solving my problem :D. I thought it was some hardware issue, but it made no sense as it only occurred as I switched between bright and dark pages. Thanks again for putting my mind to rest about a potential hardware issue :).
     
    TechOutsider, Dec 10, 2011
    #4