One of my Mac Pro 5,1 machines has a problem with boot screen boot drive selections via the Option key. Specifically, if the Option key is held the machine shows a gray screen, and freezes. So it never shows the bootable drives to allow one to be selected. It instantly restarts if the power button is pressed. Other startup keys seem to work OK, and it can be put in Target Disk mode, the Recovery Partition, or Safe Mode with no problem. The keyboard is known to be good.
This machine always seemed to have some issue with the Option key at startup. At first it would show some but not all of the bootable drives. Now it does not show any drive choices at all for the Option key startup. The boot screen is otherwise normal, and the machine runs fine with all the installed operating systems (10.6 ~ 10.14). I sure would like to regain the ability to select the drives from the boot screen; SL does not recognize APFS drives and to get back to 10.14 from SL requires stepping back through several intervening OSX visions to get to one that recognizes those drives. I have tried all the obvious quick fixes like SMC, NVRAM resets and nothing seems to help.
The machine received the expected firmware updates when I installed 10.13/10.14
The Boot Rom version is 138.0.0.0.0
Here are the machine specs:
Mac Pro 5,1 (2010)
3.33 Ghz Xenon single processor
32 GB RAM
ATI Radion HD 7950 Mac Edition
Multiple versions of MacOS, the primary OS is 10.14.5
Thanks,
John
This machine always seemed to have some issue with the Option key at startup. At first it would show some but not all of the bootable drives. Now it does not show any drive choices at all for the Option key startup. The boot screen is otherwise normal, and the machine runs fine with all the installed operating systems (10.6 ~ 10.14). I sure would like to regain the ability to select the drives from the boot screen; SL does not recognize APFS drives and to get back to 10.14 from SL requires stepping back through several intervening OSX visions to get to one that recognizes those drives. I have tried all the obvious quick fixes like SMC, NVRAM resets and nothing seems to help.
The machine received the expected firmware updates when I installed 10.13/10.14
The Boot Rom version is 138.0.0.0.0
Here are the machine specs:
Mac Pro 5,1 (2010)
3.33 Ghz Xenon single processor
32 GB RAM
ATI Radion HD 7950 Mac Edition
Multiple versions of MacOS, the primary OS is 10.14.5
Thanks,
John