Mac Pro Display Problems

Discussion in 'Mac Pro' started by Tcarrollphoto, Feb 15, 2019.

  1. Tcarrollphoto macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #1
    Hi all,

    I have a problem with an Apple LED Cinema Display on a 2009 Mac pro, I can only get it to work if i have my old cinema display plug in as well.

    I got the display on Monday to replace my old tired one but i am unable to get it working on its own. It works fine with both plugged in and i can make the new one the master display but if i unplug the old one the screen just goes off.

    this is my mac pro setup,

    Mac Pro (Early 2009)
    2.66 GHz Quad-Core Intel Xeon
    6 GB 1066 MHz DDR3
    AMD Radeon HD 7950 2048 MB
    Crutial BX 240GB SSD

    Running Os Mojava

    If anyone could help i would really appreciate it.

    Thanks in advance
    Tom C
     
  2. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #2
    Are you sure your GPU is the 7950, but not 7850 flashed with 7950 Mac EFI?
     
  3. Tcarrollphoto thread starter macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #3
    How would i be able to check and would that make the diffrence because it works as a main screen when both are plugged in
     
  4. tsialex, Feb 17, 2019
    Last edited: Feb 17, 2019

    tsialex macrumors 68040

    tsialex

    Joined:
    Jun 13, 2016
    Location:
    Brazil
    #4
    HD 78xx series don't have the exact same display outputs as HD 79xx, so when using multi-monitors this type of thing arises when cross-flashed with HD 7950 Mac Editon EFI. One common problem of HD78xx with HD79xx firmware is that HDMI don't work anymore.

    Look at the label on the card.
     
  5. verdejt macrumors 6502

    verdejt

    Joined:
    Jul 19, 2011
    Location:
    Central Florida
    #5
    That's why when I bought my flashed GTX680 I made sure that all the ports worked even when booting up. I saw a lot of flashed cards that stated only the DVI would work or Display port only.
     
  6. Tcarrollphoto thread starter macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #6
    Ah right so even tho they work when linked together the newer display port one won''t work on its own with the 850?
     
  7. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #7
    Flash the original ROM back to the card. You will lost the boot screen, but the card should able to work as expected
     
  8. Tcarrollphoto thread starter macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #8
    Ah right ok. not to sound like a newbe but how do i go about doing something like that?
    --- Post Merged, Feb 17, 2019 ---
    Just checked the card and it is an XFX R7850 2GB
     
  9. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #9
    1) Go to get a ROM that match your card’s model

    https://www.techpowerup.com/vgabios/?manufacturer=XFX&model=HD+7850

    2) Install / boot to Windows

    3) download and run ATIWinFlash as admin

    4) dump and backup your current ROM

    5) flash (program) the downloaded ROM (from step 1) to the card.

    Anyway, XFX 7000 series card has lower than normal compatibility on cMP, don’t expect too much. It may not work at all.
     
  10. Tcarrollphoto thread starter macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #10
    What cards would be best for this monitor as this card has been flashed?
     
  11. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #11
    Sorry for my poor English. You mean you want another card for your monitor?
     
  12. Tcarrollphoto thread starter macrumors newbie

    Joined:
    Feb 15, 2019
    Location:
    Liverpool
    #12
  13. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #13
    In general, avoid XFX. The others are pretty much the same, but Sapphire usually has good outcome because they produce the genuine Mac Edition card.

    The best option is the reference card, which means, has identical ports layout as the genuine HD7950 Mac Edition card.
    image.png
     

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