Take the 2-minute tour ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.

I have a friend with a mac pro 2008 model - which is failing to boot. Windows 7 was the predominantly used OS on it, and she hardly ever booted into OSX Snow Leopard. She did change the graphics card at one point, but I dont think she booted into osx once after installing the replacement gfx card (xfx 6870).

She tried to boot into OSX by holding the option key - but just received a blank screen and no video output. When booting into windows, and selecting the 'boot into osx on reboot' option - now there is no video output at all - and no option to select boot OS - so we're really stuck now. There are two chimes on boot.

I really have no experience with Macs - and have no idea where to start troubleshooting this problem. Any help would be appreciated!

Edit: I have done some reading and possibly the reason there is no video is because the xfx 6870 model has not been flashed, and doesnt support the efi-bootcamp menu.

Edit: Are there any keyboard shortcuts to select the OS on the bootcamp os select menu?

Edit: Finally got windows 7 booting again after digging out the broken 8800GT. Now just need an idiot-proof guide on flashing the 6870 so it works in osx!

Edit: After doing some reading - it appears that the last version of snow leopard should have support for the 6870 - so I will probably try booting to OSX with the old card, then running the system update - and hope that the old gfx card does not fail completely during this time. Then - if we can boot into OSX with the 6870, we will try using this zeus tool http://www.groths.org/?tag=zeus - which appears the easiest way to flash the card.

share|improve this question

1 Answer 1

You could try setting the PRAM. I think that was still effective on those models. But you are probably right about the graphics card. You can still pick up "cheap" cards from places like Powermax or powerbookmedic or owc

share|improve this answer
Would mountain lion support the 6870 out of the box? Is it worth just trying to upgrade? Tried resetting the pram - I think it's because the osx installation has never been setup to use the 6870 and we cant see the bootcamp menu.. –  Andrew B Oct 21 '12 at 23:16
It might. I found this thread: insanelymac.com/forum/topic/… –  David DelMonte Oct 22 '12 at 0:42
and this one. tonymacx86.com/mountain-lion-desktop-support/… –  David DelMonte Oct 22 '12 at 0:42
You may need to use a second computer to boot from, using the main as an attached system, then add/replace the kexts. Sorry for all the comments, I keep pressing RETURN by mistake. –  David DelMonte Oct 22 '12 at 0:43

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.