Q: 2009 Mac Pro will not boot with the Apple 27" LED Cinema Display
My 2009 Mac Pro (4,1) will not boot with the Apple 27" LED Cinema Display attached to the display port. I boots normally with my 30" Apple Cinema Display attached to the DVI.
I assume the 10.9.2 update broke the native drivers for the 7950 GPU and also assume Apple will need to make the correction ina future OS update. However, if others with this GPU are having no problems with 10.9.2, then I can look elsewhere for possible solutions.
Please let me know if you are having no problems!
Thanks,
Dave
<Edited by Host>
Posted on Sep 3, 2016 11:22 PM
I may have at least a partial answer for you.
Important question is....when you boot and look in system profiler at "About This Mac" is the 7950 id'd as "AMD Radeon 7xxx" or "AMD Radeon 7950"?
I just recreated your problem, quite repeatable, but only when the rom switch is in PC position, ie booting via self initing drivers.
If in the EFI position, it works fine. I have a 24" Apple LED and a 27" Apple LED running 10.9.2.
It is bad enough in PC position that just connecting the Apple Display causes machine to crash and reboot.
Posted on Mar 1, 2014 5:49 PM