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Displays Windows brightness control works in reverse post-LCD replacement

Discussion in 'Tech Support' started by thewelshbrummie, 24 Aug 2013.

  1. thewelshbrummie

    thewelshbrummie Active Member

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    Have a problem that I can't solve.

    I changed the screen in my netbook after it was damaged on holiday - bought off of eBay but I matched the display numbers and am certain it is the same as the one removed from the netbook.

    Its a Toshiba NB550D netbook, with 4GB Ram, a Samsung 830 256GB SSD and windows 7 Home Premium 32bit. The installation was made by using the recovery discs I made from the original recovery partition and upgraded via the anytime upgrade tool.

    It works perfectly but the brightness controls now work in reverse i.e. increasing the brightness control in Windows actually reduces brightness. The same is true in reverse. It happens both when using the brightness function keys on the keyboard and when changing the brightness slider in the power settings.

    I've found plenty of forums with people having this problem with a variety of different laptops, different brands, where on changing the display that have had this problem. I've yet to find a fix.

    I'm not sure what's causing it. I thought it was something within windows that's causing this behaviour but I swapped on the original HDD with the original win7starter OS as shipped which also has the issue. So I have no idea what I need to do to fix it.

    Any ideas? Obviously it's a minor issue and I can live with it as it is but would like to get it working correctly again.
     
  2. saspro

    saspro IT monkey

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    Have you plugged the inverter round the wrong way whilst installing the new display?

    Does it do the same thing on an external monitor if you turn the netbook display off?
     
  3. thewelshbrummie

    thewelshbrummie Active Member

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    The inverter came with the new monitor so was pre-installed and I'm sure was the right way round, it certainly looked identical to the old display... certainly worth checking though. I know the cable is in correctly, it only fits one way in the socket.

    Will try an external monitor and report back.
     
  4. thewelshbrummie

    thewelshbrummie Active Member

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    The inverter looks like it's installed correctly.

    Interestingly though external video output doesn't work. The display option is a generic output on VGA option... which isn't right since there's no VGA output, it's HDMI. Suggests that a driver of somekind is missing but can't think what it could be.

    It's got 7 Home Premium installed so can extend sideways as disabling the netbook display.
     
  5. saspro

    saspro IT monkey

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    I had a chat with our panel supplier and it looks like it could be a panel issue, you may need to swap the panel again to resolve it.
     
  6. RichCreedy

    RichCreedy Hey What Who

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    it's possible the panel has been incorrectly flashed to work with something else (dell used to have specially flashed panels, sometime reversed connectors)
     

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