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MP 1,1-5,1 Issues installing Mojave on SSD 2009 cMP 5,1

brokenmacfan

macrumors newbie
Original poster
Sep 27, 2020
2
0
Amarillo, Texas
I have a little problem. Brief history: I recently purchased a used 2009 Mac Pro that had already been upgraded to 5,1 firmware and was running Mojave ok with a Radeon RX580 video card. I was aware of the inability to get a boot screen because of the video card. I wanted to make sure that the previous owner hadn't installed some weird malware on the small SSD he provided, so I took one of my old SSDs that was laying around and decided I was going to do a fresh install of Mojave.

After some research and trial and error (still booted just fine during this), I created a boot image on a thumb drive. I also tried installing Mojave on the new SSD by itself while inside of Mojave ( on the working SSD ) but when the Mac rebooted, I got a black screen. I am assuming that had something to do with the "no boot screen due to the RX580" issue. So I removed that SSD and created the flash drive boot image. During the black screen, if I pressed "Enter" on the keyboard the Mac would restart but nothing ever came up on the screen. Once I removed that SSD it restarted fine and I was able to make the boot image. I changed the restart order to the flash drive, and restarted the Mac. At that point it restarted a couple times (with sound) but screen remained black like it did before. However, now I can't even get the Mac to start with the flash drive removed (guessing because it's trying to boot off the drive?).

And It is doing the same thing as it did when I tried the other way, you get tone, then nothing. But if you hit "enter" on the keyboard it will restart again. If you hit -> (arrow right) and enter the Mac shuts down completely. So, my question is: I have an old video card coming via eBay that I could use to be able to see the boot screen, would I be able to load Mojave right away or will I have to install High Sierra first using the old video card and then swap the cards and upgrade to Mojave? I have searched for answers but nobody seems to be having the same issue. Again, it was verified the firmware was 5,1 and it was running Mojave fine. Maybe it's trying to upgrade the firmware again before installing the fresh Mojave but I can't see the boot screen without the old video card??Any help would be appreciated. Thanks!
 

tsialex

macrumors G3
Jun 13, 2016
8,390
8,925
If you keep just the createinstallmedia USB drive and a blank SATA SSD/HDD installed on your Mac Pro (no other bootable drive connected via USB/FireWire/PCIe), your Mac Pro will boot from the createinstallmedia USB key and after 3 minutes more or less you will have the display working with the macOS installer running since macOS Installer/Recovery has the RX 580 drivers and when the AMD drivers are loaded the display will work.

Please learn to use the search, the workaround of using a card without pre-boot configuration support is know for years with hundreds of posts similar of yours.
 
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tsialex

macrumors G3
Jun 13, 2016
8,390
8,925
Btw, RX 580 support starts with 10.12.6, no earlier macOS release will work.

If your Mac Pro have a superseded BootROM, 144.0.0.0.0 is the current release, you will need to install High Sierra first, then upgrade to Mojave after.

Read the first post of the thread below:

 
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brokenmacfan

macrumors newbie
Original poster
Sep 27, 2020
2
0
Amarillo, Texas
My issue is more about why the first SSD that was working is not working now. I haven't seen anyone with this same problem. I have searched many forums and Googled different ways of asking it. So I have used search and I'm a little insulted by your accusation. I should've known better than to join this forum and ask a simple question. I'll move on to a place people are a little more helpful and a little less sarcastic and rude.
 

tsialex

macrumors G3
Jun 13, 2016
8,390
8,925
I'm baffled, this is being sarcastic and rude?
Please learn to use the search, the workaround of using a card without pre-boot configuration support is know for years with hundreds of posts similar of yours.

On the other hand, your last post for sure was.
 
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