Another cMP 5.1 not booting up thread

[stix666]

I have a similar problem with a 5:1 Mac. This has 2 Samsung evos in a RAID as the OS via PCIE. However, I also have startup disks in the SATA II slots and also an external USB drive with High Sierra installed (created using 'Install Disk Creator')

Connected to the 4k monitor, the screen stays blank
Connected to a mini projector, I get a 720p output which shows the apple splash screen.

I have reset PRAM, NVRAm.
I have tried booting in recovery mode and to to get the boot selector screen but these don't appear to work. When I try, it remains on the apple splash screen with no boot progress bar. I have the stock graphics card (Radeon 5770)

Any ideas?

In the past I upgraded the OS on a non-RAID disk and CCC to the PCIE raid afterwards. This time, I can't get that option.

 

[Naimfan]

You might try removing every drive and peripheral save a single spinner; then try to boot to recovery.

If that doesn't work, try to install Snow Leopard from a DVD.

Also - are you able to run Apple Diagnostics?

 

[h9826790]

Did you ever use the recovery partition?

I don't think 5770 can display 4K boot screen. It may not even support 4K at all.

Are you using a wired keyboard? If you can see the Apple logo, you should able to use the start up manager (holding option during boot).

 

[rawweb]

I don't think 5770 can display 4K boot screen. It may not even support 4K at all.

Correct, max resolution on a HD 5770 is 2560 x 1600. No 4K support.

For what it’s worth: https://arstechnica.com/civis/viewtopic.php?f=19&t=1296845

 

[stix666]

Thanks for the tips. I think I need to remove all the drives bar one and try again. Have already tried to get into recovery mode; and pressing option during boot - but those boot selector and recovery options do not appear.

The Mac pro worked with this display before at 4k 30Hz; but I think I'll change the output down to 2560 x 1600 on the display settings. If it doesn't work, no biggie as the projector works fine for now