Refurbished Mac Pro 5.1 will not boot in any mode

[thetokay]

Hi all,

Refurbished Mac Pro 5.1 running Mojave has stopped booting after a couple of crashes - I have reset SMC and the NVRAM, but booting into any mode, Safe or otherwise, is impossible - as soon as the boot sequence hits the apple logo and loading bar, it freezes. I can boot into Alternative Startup mode, but loading into my Windows partition crashes as soon as the Windows logo appears. Trying to boot into an external install disk also freezes at the loading bar.

Any ideas? Thanks for your time

 

[Maxwideman]

Hi thetokay, I don't have an answer but I do have a question. You say you are (or were) running OS 10.14.x on a Mac Pro (mid 2010) - right? Then since the limit of this machine is OS 10.12.6 you must have upgraded, ie with an 8GB Radeon card or similar to extend the OS range.
My question is: Do you add that card to your machine, or do you have to replace the existing card? Do you have to do anything else as a part of the installation? My point is, can you back track to your previous configuration?
Bear in mind that older programs like dreamweaver will apparently not run on anything newer than OS 12.