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    T420 blank screen?

    Discussion in 'Lenovo' started by bleesan, Jul 24, 2011.

  1. bleesan

    bleesan Newbie

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    Hi all,

    I have a brand new T420 (received a couple of days ago) but on my second time booting the system the screen turns blank. I can get into windows 7 on normal mode and through the login screen. The desktop then shows up for a couple of seconds but suddenly the screen turns black. The computer responds to commands (makes sound when I press Esc key) but I cannot see anything.

    I tried going into Safe Mode and attempted Lenovo's recovery program (F11) at startup but the screen goes blank before I'm able to see anything. I can get into the BIOS though.

    Does anyone know what the problem is? I've talked to tech support and they suggested to send the machine back for repairs. I have a feeling that Optimus is causing problems though.

    Overall I'm quite disappointed! I had a T30 and T61 and they worked without problems for 4+ years! If anyone knows any solutions or has encountered similar issues please let me know...much appreciated for your help!

    Thanks,
    Ben
     
    bleesan, Jul 24, 2011
    #1
  2. John Ratsey

    John Ratsey Moderately inquisitive Super Moderator

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    If you can get into the BIOS then check for an option to disable Optimus. I think one exists (but I'm running an Intel-only machine). If you can fix the GPU in the BIOS then you can see if the problem disappears.

    Also check that you are using the latest BIOS and drivers.

    John
     
    John Ratsey, Jul 24, 2011
    #2
  3. bleesan

    bleesan Newbie

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    Hi John,

    Thanks for your input. I've tried doing this, but wasn't successful. One thing that was interesting was that every time I selected 'discrete graphics only' through the BIOS and saved, the problem still exists but the next time it occurred, the setting went back to Optimus. So I don't really know what is going on.

    Thanks,
    Ben
     
    bleesan, Jul 24, 2011
    #3
  4. kirayamato26

    kirayamato26 Notebook Deity

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    Change the setting below it to Disabled.

    Try pressing Fn + F7 or whatever that hotkey is for switching displays and press enter, it could be that your T420 is trying to send the display signal to an external monitor.
     
    kirayamato26, Jul 24, 2011
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  5. bleesan

    bleesan Newbie

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    Thanks for your input!

    Ok, so here is a bit of positive news. This time I managed to fully deactivate Optimus. I can get into the desktop successfully. However there is a catch - when I close the lid and turn my computer back on the blank screen comes back. So it seems to be an Optimus issue. Also tinkering with the settings in the Power Manager also seems to be screwing things up (eg setting it to max battery life: I believe the computer changes the graphics and the blank screen comes back).
    I'll try updating drivers/BIOS and see how it goes.

    Thanks
    Ben
     
    bleesan, Jul 24, 2011
    #5