10 Replies Latest reply: Feb 4, 2013 9:58 AM by The hatter
iPhoneNerd54 Level 1 (25 points)

i have a flashed ATI 5870 on my Mac Pro 1,1. i have recently purchased a DVI-VGA adapter so i can hook up to TV. i get the apple logo but then it goes out and the tv does not detect the signal, HDMI works fine on my tv( no boot screen). i dont know whats going on

iPhone 4S, iOS 5.0.1
  • Grant Bennet-Alder Level 9 (56,612 points)

    VGA is a very special case when using a DVI connector. It is NOT a conversion, just a re-wiring.


    The Analog VGA signals are produced directly by the Hardware, and are provided on the bar at the end of the connector, the four pins around it, and one more pin at the end of the grid. These are picked up by the adapter and rewired to their proper pins on the VGA side. The bar is the common return.




    salmon pink color in the diagram above, courtesy of Wikipedia.


    ANY picture, however momentary, indicates the Hardware is working.

    It couls also mean that once the Driver starts up, and shifts to a higher resolution, that resolution is out-of-range.


    This may mean that the flashed PC card does not support that usage.


    For a further experiment, try booting from an Installer DVD if you have one, or invoking Safe Mode. Both of these use the "simple" driver throughout, rather than the kext driver.


    EDIT: HDMI is a simple re-wire of the digital DVI signals. No converson is perrformed in the adapter.


    If you are trying to run THREE displays at once, special rules apply. Debug with only two connected.

  • iPhoneNerd54 Level 1 (25 points)

    Im only trying to run 1 monitor. yeah im confused boots up then after logo. No signal

  • Grant Bennet-Alder Level 9 (56,612 points)

    Try holding the Shift key at Startup to invoke Safe Mode. Safe Mode spends five minutes running Disk Utility ( Repair Disk ) then opens to a login screen. You must login with your username and password, even if you normally auto-login.


    Since Safe Mode loads very few kernel extensions, the screen is run in "simple" mode. If you use:


    System Preferences > Displays ...


    ... to Actively reset the screen resolution to something really easy, like 640 by 480, and close the window and save changes, you may have better luck when you start up normally.

  • iPhoneNerd54 Level 1 (25 points)

    hello i tried. i get a blank screen (no apple logo) then switched to no signal.

    i then connect via hdmi and i get to the log in screen and its normal i did set to 640 by 480 and then restarted and same thing again.

  • iPhoneNerd54 Level 1 (25 points)

    i just tried again, i did get a logo and spinning gear but then switched to no signal. everything this happens i hear the fans on the card get a big high then low again

  • iPhoneNerd54 Level 1 (25 points)

    Quick Update: i managed to find a monitor which as a VGA input and i went ahead and plugged in my mac pro. same thing. Apple logo then no signal.

    then my friend let me borrowed his x1900xt and no problem at all using the dvi-vga adapter.

    im guess is my card then, so what now?

  • Grant Bennet-Alder Level 9 (56,612 points)

    Many users with Mac Pro 1,2 or 2,1 or even 3,1 computers have experienced graphics card failures. The simplest solution has been to get the Apple-firmware 5770 (about US$250) and upgrade to 10.6.5 or later to get the drivers.


    Apple has not tested it in these older models, but users here assure us that the Apple-firmware card (preferably genuine Apple, not flashed) works in all Models Mac Pro. The flashed PC-cards tend to not show the boot-up screens, which is inconvenient.

  • iPhoneNerd54 Level 1 (25 points)

    im currently running with Lion

    like i said before

    Yes hdmi connection but no Dvi-vga on 5870

  • The hatter Level 9 (60,930 points)

    flashed cards often only support one output port, you tried that?


    Macvidcards ebay supports Mac Pro but nVidia cards mostly