Mac mini showing black screen at login after macOS 12.3 update

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Mac mini showing black screen at login after macOS 12.3 update

Hello everyone. I updated my Mac mini 2018 with the last update of macOS Monterey. I see the Apple logo but the login screen is no more visible. I tried the followings:

Safe Reboot: everything's fine, until I reboot normally.

NVRAM Reset: nothing changed.

Recovery Boot with Disk repair: no errors.

Formatted the whole Macintosh HD then installing Monterey 12.3 pendrive and restoring a 5 days ago backup: same black screen at login.

During the installation I noticed my monitor was having strange colors at restart/reboot. All gray, all green and of course all black at last. After 8 hours I have to give up.

PS. My Mac mini is visible on a network. I tried to control the screen, but shows black on Remote Desktop.

Anyone having the same? Ideas? Thank you for reading.

Posted on Mar 15, 2022 3:23 PM

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Answer 1

Best reply

Robbbbbbbbiiiiiiieeeeee

Level 1

52 points

Mar 16, 2022 9:55 AM in response to macraider

Like you, I only got the lower refresh rates using the Thunderbolt to DisplayPort cable between Mac mini and LG monitor.

So I used an HDMI cable to HDMI cable and get the same refresh rate and resolution I got with the DisplayPort , but it's not as sharp.

It IS a reasonably good HDMI cable. Maybe that makes a difference?

Hopefully Apple will address this.

Best of luck.

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Answer 2

vovnit

Level 1

13 points

Mar 16, 2022 12:13 AM in response to macraider

Load from Safe mode and change resolution to one without scaling.

I had to clean reinstall MacOS to figure this out. With native monitor resolution everything is working fine, but once scaling resolution is turned on, everything goes dark. I hope it's going to be fixed real soon.

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Answer 3

macraider Author

Level 1

80 points

Mar 16, 2022 3:22 AM in response to macraider

Just spoken with Apple Support. Just a software update and the specs are changed. The Thunderbolt ports doesn't work anymore with that frequency. I have a LG 27UK850 monitor (LG) and I was using the Thunderbolt port on both devices. I tried a USB-C to HDMI and "works", but I don't like it at all. New resolutions are 2560 x 1440, 3008 x 1692, 3360 x 1890, all three with 30 Hz frequency. For what I can see, is flickering a bit, was a better view with Thunderbolt. I wonder why they did put frequency limits on the Thunderbolt ports. I'm all except happy, but for now I can't do much. Thanks Apple, not a good job.

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Answer 4

Mar 16, 2022 9:01 AM in response to macraider

I just want to thank everyone, especially the OP for this thread. I had the same problem on my 2018 mac mini. Monterey 12.3 installed and my LG 27UK850 monitor, with displayport cable, was black.

Having spent nearly 24-hours on this, total system wipe, reset firmware etc.... tiresome, the posts here saved me a visit to the Genius Bar.

It's not the first time that Apple hasn't played nicely with the LG 27UK series of monitors.

I'm now using the HDMI port from the Mac mini to monitor now. The picture isn't as sharp in my opinion, although I am getting 60 Herts refresh. And I've lost the use of two monitors, but the system works.

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Answer 5

macraider Author

Level 1

80 points

Mar 16, 2022 9:42 AM in response to Robbbbbbbbiiiiiiieeeeee

I'm now using the HDMI port from the Mac mini to monitor now. The picture isn't as sharp in my opinion, although I am getting 60 Herts refresh. And I've lost the use of two monitors, but the system works.

Robbbbbbbbiiiiiiieeeeee wrote:

I just want to thank everyone, especially the OP for this thread. I had the same problem on my 2018 mac mini. Monterey 12.3 installed and my LG 27UK850 monitor, with displayport cable, was black.

Having spent nearly 24-hours on this, total system wipe, reset firmware etc.... tiresome, the posts here saved me a visit to the Genius Bar.

It's not the first time that Apple hasn't played nicely with the LG 27UK series of monitors.

I'm now using the HDMI port from the Mac mini to monitor now. The picture isn't as sharp in my opinion, although I am getting 60 Herts refresh. And I've lost the use of two monitors, but the system works.

60 Hz? Really? Same monitor here. With Thunberbolt to HDMI I only get 30, 25, or 24 Hz (terrible!) and not even the UHD. I've tried a HDMI to HDMI but is not apparently working, do you think is a matter of cable? I'll give a chance to try a Thunderbolt to Display Port.

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Answer 6

macraider Author

Level 1

80 points

Mar 16, 2022 10:05 AM in response to Robbbbbbbbiiiiiiieeeeee

Well, this actually solved my trouble. I tried another HDMI to HDMI with golden connector (I use with Apple TV 4K), and working good! The picture is not bad at all, you know. Try the many combinations of settings to obtain the best quality. I can share if you want.

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Answer 7

Mar 16, 2022 10:29 AM in response to macraider

Thank you for the offer of settings, but the picture isn't terrible. I do feel the DisplayPort path offers a better result, so I'm going to go back to that once Apple fix this.

Glad you got it sorted out.

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Answer 8

Mar 17, 2022 1:37 AM in response to Stingray1978

My set up involves a 4k monitor and a 1k monitor. I'm using a HDMI for the former (previously DisplayPort cable) and a USB-C adaptor to HDMI for the latter and have thus got my original set up back, using HDMI on both.

As a curio, I plugged my 4k monitor into my second Mac mini (2018) -- using the DisplayPort cable that I've used these past few years on my main Mac mini -- and it worked fine at 4k and 60Hz WITH scaling. <shug> Conclusion: Monterey 12.3 allows NEW set ups involving Thunderbolt to DisplayPort, but not existing ones. At least that's my experience.

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Answer 9

Mar 17, 2022 1:54 AM in response to Robbbbbbbbiiiiiiieeeeee

My current work-around to use 2 displays, is to connect one of them twice both via HDMI and USB-C giving me 3 displays in total... I then mirror the image on one of the screens as I only have two physical monitors ... go figure ... it seems that 3 screens don't make any problems

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Answer 10

t33j4y

Level 1

4 points

Mar 21, 2022 11:07 AM in response to macraider

For some strange reason, my initial post about this seems to have been deleted...

Anyway, the fix is to change your monitors DP version to 1.2 from the OSD menu. Some monitors might not support this, though.

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Answer 11

macraider Author

Level 1

80 points

Mar 21, 2022 11:56 AM in response to t33j4y

Indeed I received a notice but I didn't see the post, I have read it by mail, though. Unfortunately my monitor is not the newest and those settings are not visible. For now I keep HDMI connection, although a few days ago, I saw black again in the middle of my work. I had to force restarting then was ok again. I hope they will fix this, btw I'm waiting for my Mac Studio soon, replacing my Mac mini, possibly having the same issue with Thunderbolt. Or maybe I need a quality cable, I didn't have try yet.

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Answer 12

macraider Author

Level 1

80 points

Mar 30, 2022 11:43 PM in response to Stingray1978

Same here... my Mac Studio (replacing the Mac mini) has arrived two days ago, but I didn't have the same luck. Just out of the box I connected to my LG 27UK850 by thunderbolt and was showing just 1/5 of the screen, apparently. I had to connect with a Thunderbolt to HDMI cable to see something but with 30 HZ frequency. Usable but I think is flickering a little bit. What monitor and connector/cable are you using?

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Answer 13

t33j4y

Level 1

4 points

Mar 31, 2022 1:37 AM in response to macraider

I found a mail from the forum admins stating that my post had been removed as I referenced a beta release. Kind of an overreaction since I didn't divulge anything. I don't even use or have access to betas as far as I know. But nvm.

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Answer 14

macraider Author

Level 1

80 points

Mar 31, 2022 4:07 AM in response to Stingray1978

Stingray1978 wrote:

I use two 4K MAG321CURV from MSI. One connected via HDMI 4K 60 Hz, scaled to 2K and the other the same via USB-C to Displayport. No problems so far.

My LG with Mac Studio shows black with more than 30 Hz with Thunderbolt to Thunderbolt cable and HDMI to HDMI. Thanks anyway, don't want to OT

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Answer 15

macraider Author

Level 1

80 points

Mar 31, 2022 11:12 AM in response to Stingray1978

Stingray1978 wrote:

Apple apparently just pushed a fix…

https://www.macrumors.com/2022/03/31/apple-releases-macos-monterey-12-3-1-with-bluetooth-and-display-fixes/

Wow, thanks I missed it. I'll look forward to try it

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Mac mini showing black screen at login after macOS 12.3 update

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