MP 1,1-5,1 Mojave Update gone bad

[Steve_Jones]

Last night I attempted to update my Mac Pro 5,1 to the latest beta but the update failed. After waiting a couple of hours, I rebooted the machine but nothing.

I swapped out the RX580 video card for my original video card so I could see any start-up messages and as I expected, the machine couldn't find OSX.

I ran disk utility and it came back clean as I suspected it would. I tried reinstalling Mojave from the prompt but it won't install since I've got my older video card in.

My next step was going to be a bootable USB stick but it appears I must select it from recovery mode which means older video card which means no Metal support and back to square one. Knowing that there's no OS on any of my installed drives, would the machine know enough to boot from usb?

Is it possible to have both video cards in at once? I see only two power connectors and the RX580 uses both. Would one supply enough power to the RX580 temporarily while the old card is in?

Is there an easier method I'm overlooking?

BTW, with the posts in this forum, I've swapped my video card in order to run Mojave, upgraded my CPU from a quad core to a hex core, installed faster memory and a 5 port usb3 card. My 9 year old computer suddenly has a new life. You guys rock!

 

[h9826790]

Only install the RX580.

If you want to boot from the USB drive, hold C to boot.

If you want to boot from recovery partition, hold Command + R to boot.

Then you can install Mojave from either of them.

Anyway, my suggestion, for cMP, always keep at least one bootable clone / backup OS drive. And at least one recovery partition available to you. This will make your live much easier when something goes wrong.

 

[Steve_Jones]

I thought the problem with those methods is that the non-Mac edition RX580 didn't show recovery or boot screens?

I've tried command-r for recovery mode but after a bit of hard disk noise, I don't hear anything and my screens are blank.

Another edit:

Only connected one monitor and got into Recovery mode. Selected Reinstall MacOS and it dumps me to a macOS Mojave Beta screen which tells me a firmware update is needed. Strange, I thought my firmware was already up to date? Clicked on shutdown button but that seemed to just change the button from grey to black. Selected shut down from the menu and it seems to have gone through the firmware update. Waiting patiently......

 

[h9826790]

I thought the problem with those methods is that the non-Mac edition RX580 didn't show recovery or boot screens?

I've tried command-r for recovery mode but after a bit of hard disk noise, I don't hear anything and my screens are blank.

Both method don't need boot screen, that's why I recommend it.

Command + R only work if there is a recovery partition. If there is no recovery partition in your Mac at this moment, it won't work.

Since you said "screens", I assume you have multiple displays. Disconnect all of them but one. Single screen work better for recovery.

 

[Steve_Jones]

Thanks. Mojave appears to be reinstalling so I assume I've got a recovery partition.

 

[MarkC426]

Generally it’s not a good idea to install beta’s without a sensible backup solution.
Just wait until the official release.

 

[AidenShaw]

Generally it’s not a good idea to install beta’s without a sensible backup solution.
Just wait until the official release.

It's not a good idea to install official releases without a sensible backup solution.

 

[Steve_Jones]

Looks like the dual monitor setup was the problem. All back online now.

Thanks for your help!