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MP 1,1-5,1 Please Help! Black screen after PRAM/NVRAM Reset - MacOS Mojave

loonysumo

macrumors newbie
Original poster
Jul 7, 2020
3
0
Hi everyone,

I hope you can help me with this: I’m currently getting a continuous black screen after doing a PRAM/NVRAM reset.

This is my computer:
Mac Pro 4,1 -> 5,1
CPU: W3520 Xeon Processor
GPU: Sapphire Pulse RX580 8GB
RAM: 24GB RAM 1333mHz
1TB SSD
MacOS Mojave

This is why I tried a PRAM/NVRAM reset:
  • When the computer ‘restarts’ I always encounter the ‘prohibitory’ symbol, ie. a circle with a line through it (example: https://support.apple.com/en-gb/HT210901). However, a shut down and then booting does not lead to any problems, only if the computer is restarting. This has always been the case with my computer.
    • Also I’d like to note that a third chime followed releasing the buttons [command]+[option]+[p]+[r] directly after the second chime. I tried again, and holding down the four keys leads to endless chimes until I release them
My preference is to downgrade to High Sierra again / reset the SSD and do a clean install, however how do I get into recovery mode now with Mojave? With the original GT120 card?

Things I noticed:
  • I think I remember a white light switching on with the GPU, that no longer appears (or never did, and I don't remember properly). The fans are running at least, also the computer's. And the display suggests it is receiving a signal, only it's just staying black.
If you need more info, please let me know.

Best,
loonysumo
 

loonysumo

macrumors newbie
Original poster
Jul 7, 2020
3
0
Nope. It all stays black going into recovery mode.

However, I did get my display back. I connected my boot drive to my MacBook to check if it was working (and it did) and also decided to uninstall the Nvidia web driver (didn't need it anymore). I also unplugged my monitor and changed from DP to HDMI and somehow it got working again. Phew! So either one of the two or both worked.

Nonetheless, the computer still gets stuck while restarting... so I end up switching it off and then booting it.
 
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nobullone1964

macrumors regular
Oct 20, 2018
129
33
Nope. It all stays black going into recovery mode.

However, I did get my display back. I connected my boot drive to my MacBook to check if it was working (and it did) and also decided to uninstall the Nvidia web driver (didn't need it anymore). I also unplugged my monitor and changed from DP to HDMI and somehow it got working again. Phew! So either one of the two or both worked.

Nonetheless, the computer still gets stuck while restarting... so I end up switching it off and then booting it.
Is your RX580 brand new or used? Reason I ask is used cards may have been used for mining. I had that problem and traded up for new. Since Mojave is installed try booting with the GT120 and see if you can reboot without your ceremonial hard reboots.
 
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nobullone1964

macrumors regular
Oct 20, 2018
129
33
Is your RX580 brand new or used? Reason I ask is used cards may have been used for mining. I had that problem and traded up for new. Since Mojave is installed try booting with the GT120 and see if you can reboot without your ceremonial hard reboots.
Also, are you giving enough time to boot? The RX580 has no boot screen so you must wait until the OS is reached. Also, make sure the macOS is the default boot drive once you get into the system.
 
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loonysumo

macrumors newbie
Original poster
Jul 7, 2020
3
0
Hi Nobullone,

Thanks for your input. The RX580 is brand new.

I've given the computer a couple minutes a number of times but to no avail. I'm able to use the computer now though, the black screen issue is not there anymore, except when restarting of course.

I'll try the GT120 tomorrow and see if I can get into recovery mode that way.
So you are able to get into recovery mode with your RX580?

It's really weird why the problem only happens with a restart.
 
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nobullone1964

macrumors regular
Oct 20, 2018
129
33
Hi Nobullone,

Thanks for your input. The RX580 is brand new.

I've given the computer a couple minutes a number of times but to no avail. I'm able to use the computer now though, the black screen issue is not there anymore, except when restarting of course.

I'll try the GT120 tomorrow and see if I can get into recovery mode that way.
So you are able to get into recovery mode with your RX580?

It's really weird why the problem only happens with a restart.
Yes, I can get in recovery mode. You just have to be patient by holding down and continue holding down cmd+R. It could take up to 4 minutes for the GUI to show for recovery mode. Just hold the keys down. Now...your recovery partition could be damaged or for some reason didn't get created. If you have a recent back up I would suggest booting from USB and installing your OS again. Not from recovery mode.
 
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kohlson

macrumors 68020
Apr 23, 2010
2,421
723
I have similar cMP, but x5680 and 32GB memory. Booting from the NVMe takes a minute or so. The screen is black for much of that.
When booting into Recovery, it seems that exactly when you press the keys can make a difference. Not before the chime, and not after the chime, but during the chime - about a 1 second window. When booting into Recovery, I get bored and look at other things during this time - it takes a few minutes, maybe more. The screen is black for most of that time.
 
Last edited:
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Macschrauber

macrumors 6502a
Dec 27, 2015
994
367
Germany
Is the startup disk set ?

Prohibited sign ? Do you run a patched Version of Mojave ?

What is the Firmware Version of the Mac ?
 
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