iMac 2011 GPU Upgrade Display Problem GTX675MX

Discussion in 'iMac' started by moorhad, Dec 13, 2013.

  1. moorhad macrumors newbie

    Joined:
    Dec 13, 2013
    #1
    Hi.

    Just put a GTX 675MX in my Imac 2011.
    When i powered up the Display doesn't show anything.

    BUT....

    When the Thunderbolt Display is Connected the Desktop
    of the Thunderbolt is shown up.

    So what is wrong here?
     
  2. goodcore macrumors newbie

    goodcore

    Joined:
    Jun 24, 2013
    Location:
    Putinville
    #2
    Make photo of that. I don't understand:confused:
     
  3. moorhad thread starter macrumors newbie

    Joined:
    Dec 13, 2013
    #3
    When I start the iMac it powers on.
    But I get no screen on the iMac.
    When I connect my Thunderbolt Display
    Into the iMac I get a screen but only on the
    Thunderbolt Display.
    The screen of the iMac is black.
    It also doesn't recognize the iMac screen
    in the settings.
     
  4. goodcore macrumors newbie

    goodcore

    Joined:
    Jun 24, 2013
    Location:
    Putinville
    #4
    Now I get it. How I know, you need modified bios or drivers for videocard. Also, can you make screenshot for proofing?:p
     
  5. moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #5
    Gonna post it tomorrow...
    But if I need modified bios or something why does it work with an external monitor?
    The card is identified as a GTX 675mx 4096.
    So everything seems to be fine...
     
  6. moorhad, Dec 15, 2013
    Last edited: Dec 15, 2013

    moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #6
    So here are some Pics from my Imac...
     

    Attached Files:

  7. joe-h2o macrumors 6502a

    Joined:
    Jun 24, 2012
    #7
    You should probably hide your serial number - it's visible in those photos.

    It also sounds like the 675MX needs a custom firmware to make it compatible with the iMac.

    I assume all the internal cables have been reconnected? The iMac's internal display is run over a DisplayPort connection - this may not be visible to the new GPU if it's a port on the logic board without a specific Mac firmware.
     
  8. moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #8
    hmmm.but in the new imacs there are some which provide this card so there must be a firmware..where can i get this...?
     
  9. goodcore macrumors newbie

    goodcore

    Joined:
    Jun 24, 2013
    Location:
    Putinville
    #9
    You can talk with MacVidCards i think he can solve this problem!

    PS: thx for photos!
     
  10. joe-h2o macrumors 6502a

    Joined:
    Jun 24, 2012
    #10
    People have asked users that have the 675/680 GPUs to use the firmware dump tool to extract it so that it can be used to flash other cards, but as far as I know this has been unsuccessful with the late 2012 iMac for some reason.

    Macvidcards might have more information.
     
  11. jaxhunter macrumors regular

    jaxhunter

    Joined:
    Dec 14, 2012
    Location:
    Arizona
    #11
    I believe the 2011 iMacs used a standard LVDS connection and the 2012 and later switched to an internal MiniDisplayPort connection. They may be physically identical connectors but they used different protocols. Either that, or you missed a connection or damaged one. The two suspects would be the main data cable or the backlight cable, though if it were the latter the machine would behave as if the internal display was attached.
     
  12. moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #12
    Ok...I was a bit afraid....so I put my old card back and everything is fine..
    There is no damaged connectors...
     
  13. moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #13
    Just wrote to this guy on eBay.
    And he answered:

    Sorry, we do not work with iMacs or offer free tech support.
    Thanks !!!

    :/
     
  14. SilvioM macrumors newbie

    Joined:
    Mar 10, 2013
    #14
    What if you could get the bios from the GTX 680MX of a 2012 iMac and flash it onto the GTX 675MX? That might work
     
  15. moorhad thread starter macrumors newbie

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    Dec 13, 2013
  16. SilvioM macrumors newbie

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    Mar 10, 2013
    #16
    Probably not online. I guess you would need to know someone with a 2012 iMac.
     
  17. moorhad thread starter macrumors newbie

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    Dec 13, 2013
    #17
    I don't know someone who has this model.
    Maybe someone in this forum can do this!?
     
  18. jaxhunter macrumors regular

    jaxhunter

    Joined:
    Dec 14, 2012
    Location:
    Arizona
    #18
    The issue is not typical of a firmware issue...

    Typically if a PC video card is installed in a Mac then you will not get boot screens on any display but once the OS loads and the OS drivers are running then you get full display.

    This is a different kind of incompatability.

    Also, you should not flash a 675 with 680 firmware. Stick with like for like if you're going to play around with something like that.
     

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