Black screen in Bootcamp with PC 7950

Discussion in 'Mac Pro' started by troc, Apr 6, 2015.

  1. troc macrumors newbie

    Jun 26, 2006
    The Netherlands

    I have a problem I can't seem to resolve - or understand.

    I have a Mac Pro 2009, flashed to 2010 and running a 3.46Ghz hexcore.

    Originally, I had a flashed PC4870 in there and all was well, if a little slow.

    I bought a club 3D 7950 a while ago and was happy, despite the lack of boot screens.

    I recently decided I wanted to get a boot screen and get rid of the 7xxx in the about this mac page so I thought I'd install Windows 7 to get the flashing done as I'd long ago lost my windows drive.

    However I have run into an issue. I assumed I could simply reboot via bootcamp assistant and the windows install stuff would appear and I could install but this didn't happen. I got a black screen (no flashing curser in the top left btw) In the end I reinstalled the 4870 and did it that way. With the 4870 I get boot screens and bot OS X and windows work perfectly. So I shut down and reinstalled the 7950. However, I cannot boot into windows with the 7950 installed as I get a black screen. I know it'a booting as I hear the windows chimes and it even makes a disconnect/reconnect when I unplug the DVI cable.

    I am connected via DVI. The 7950 has DVI, HDMI and 2 miniDP on the back.

    I don't know if it's related but the GT120 in the mac also shows a black screen, whether on OS X or windows.

    I tried installing new catalyst drivers (by sticking the 4870 back in) but no change.

    Any thoughts?
  2. troc thread starter macrumors newbie

    Jun 26, 2006
    The Netherlands
    Just in case it helps. The display is a Dell 2407 with DVI-D input.

    The 4870 (which works in OS X and bootcamp) has 2xDual-Link DVI-D plus TV out

    The GT 120 has mini displayport and a dual-link DVI-D
    The 7950 has 2xmini displayport, HDMI and dual-link DVI-I

    I have only tried connecting with a DVI cable as I have no other cables or adaptors available.

    To recap:

    Radeon 4870 (flashed) has boot screens and works in OSX and Bootcamp
    Radeon 7950 (not flashed) has no boot screens and works in OSX. In bootcamp, windows boots completely but there is no display.
    GT 120 No screens, ever. Anywhere.

    Obviously I can't have the two ATI cards installed at once due to power issues. I was hopeing to be able to use the GT 120 as a fall-back card but that doesn't seem to be working.

    Is it a cable issue? Should I get a mini display port to DVIadaptor and try that?

    I do have another monitor I can grab which is a dell 2713 with DVI, HDMI and display port but I've not tried as yet.

    I'd rather like to be able to boot into bootcamp occasionally, not just to flash the card but also for the odd game that's not available under OSX......
  3. troc thread starter macrumors newbie

    Jun 26, 2006
    The Netherlands

    I fixed it by using a mini display port to DVI adaptor.


    Still have no idea why that works :)

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