Mac Pro 4.1 (5.1) Cannot restart in recovery mode

[mosw]

Hi all

I'm using a Mac Pro 4.1 (flashed to 5.1) with a non flashed GTX1060 with OS 10.12.5 and wanted to upgrade to High Sierra. To do so, I removed the GTX1060 and put my old ATI Radeon 4870 back in to be able to follow the described procedure http://dosdude1.com/highsierra/

Coming to my issue, it seems that even with my old "Apple" graphic card, I cannot go into recovery mode. Rebooting with Command-R (also tried Single-User Mode as well as Startup Manager) gives me no screen.
I already googled the issue and it seems that it somehow stuck in a loop to load the correct drivers. Therefore, I also tried uninstalling the NVIDIA Drivers but it did not help.

Does anybody have experience with this?

Thank you in advance!

 

[chrfr]

Hi all

I'm using a Mac Pro 4.1 (flashed to 5.1) with a non flashed GTX1060 with OS 10.12.5 and wanted to upgrade to High Sierra. To do so, I removed the GTX1060 and put my old ATI Radeon 4870 back in to be able to follow the described procedure http://dosdude1.com/highsierra/

Coming to my issue, it seems that even with my old "Apple" graphic card, I cannot go into recovery mode. Rebooting with Command-R (also tried Single-User Mode as well as Startup Manager) gives me no screen.
I already googled the issue and it seems that it somehow stuck in a loop to load the correct drivers. Therefore, I also tried uninstalling the NVIDIA Drivers but it did not help.

Does anybody have experience with this?

Thank you in advance!

If your Mac Pro has been flashed to be a 5,1 you don't need to use DOSDude's method to install High Sierra. High Sierra is fully supported on the Mac Pro 5,1. You can either upgrade to High Sierra just by running the installer from Sierra, or you could make a USB installer and do a clean install that way.

 

[h9826790]

If you sure the recovery partition is there (e.g. NOT running from a self created Fusion Drive that have no recovery partition etc), try a PRAM reset.

 

[mosw]

If your Mac Pro has been flashed to be a 5,1 you don't need to use DOSDude's method to install High Sierra. High Sierra is fully supported on the Mac Pro 5,1. You can either upgrade to High Sierra just by running the installer from Sierra, or you could make a USB installer and do a clean install that way.

... Didn't thought about that, just checked and see that I have 4.1 (again)... So I tried to get it back to 5.1, but it looks like it does not work. Anyway, I will follow-up on this solution.

If you sure the recovery partition is there (e.g. NOT running from a self created Fusion Drive that have no recovery partition etc), try a PRAM reset.

I tried it but it hasn't helped with the issue.
I'm also thinking about making a clean installation, but as long as I cannot but from an external source (USB or similar), I'm not sure if this is even possible

 

[h9826790]

I'm also thinking about making a clean installation, but as long as I cannot but from an external source (USB or similar), I'm not sure if this is even possible

You just said you can't boot into recovery partition. I expect you can still boot to normal OS. As long as you can do that, just run the OS installer inside the normal OS, select any other drive as the destination, then you will have a clean installation "test drive". That may even give you back your recovery partition. On a Mac Pro without multiple internal SATA port, that's very simple.

 

[mosw]

Thanks for your inputs. I managed to flash the Mac Pro to 5.1 by "blindly" disabling csrutil, which blocked the flashing and than upgrade to High Sierra the regular way.

I'm still not able to go to recovery mode, but this is not urgent - I will try it later by making a clean install.

 

[Itconnects]

I'm running 4,1 flashed to 5,1 mojave. How do I enable crustil?

 

[h9826790]

I'm running 4,1 flashed to 5,1 mojave. How do I enable crustil?

NVRAM reset is the easiest way to do it.

A more proper way is to boot into recovery partition, open terminal and enter “csrutil enable”

 

[tommy chen]

I'm running 4,1 flashed to 5,1 mojave. How do I enable crustil?

how did you turn it off if you don't know how to turn it on?

 

[Itconnects]

Yes it worked. I had to hold the keys before turning on the Mac