Holding down Option key gives black screen

[orbitalpunk]

I used to be able to get to the partition selection screen when rebooting my 2013 Mac Pro and holding down the option key. Now its just a black screen. Anyone have a similar issue and a solution to this. It used to work just fine.

 

[h9826790]

The same setup? e.g. same monitor, same resolution, etc.

 

[Synchro3]

Afaik option boot on Mac Pro 6,1 works only with less than 4K Resolution.

 

[h9826790]

Afaik option boot on Mac Pro 6,1 works only with less than 4K Resolution.

I think the last OS update 10.12.4 fixed this issue, which allow the nMP boot with 4K 60Hz, but not sure (I don't have this machine).

 

[orbitalpunk]

Yep, all the same. The only thing that's changed are macOS updates. I noticed this when installed Bootcamp and after Bootcamp partitioned the hard drives and rebooted to install windows for the first time, it was a black screen.