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macrumors newbie
Original poster
Oct 14, 2011
just updated macos and now can't use my 2nd monitor, no matter what i do it, only one monitor will work at the same time.

Any ideas?

restarted a million times and smc resets etc

2018 mac mini intel


macrumors newbie
Mar 15, 2022
got the same issue after my Mac mini 2018 upgraded to the 12.3 this morning. it was ok to display two screen at the previous version 12.2.x , but can only display one of the two screen after upgraded to 12.3


macrumors newbie
Mar 15, 2022
Argh, yet another problem with external monitors on the 2018 Mac Mini.
I have a Samsung 28" 4k monitor that was working fine in 12.2 over USB-C>Display Port cable.
Now after the update it doesn't work at all.
It does work over HDMI.

It also does work in recovery mode with USB-C>Display Port which defaults to the monitor's native resolution.

I'm wondering if it's something to do with scaled mode when connected over USB-C because I have it scaled since the native resolution causes everything to be too small and unusable.

What I've noticed is that the Mac boots and the screen works during boot, then it gets to the login screen(with auto login) and it goes black.

This is not the first time I've had problems with external monitors on this computer.
In fact, I switched to using USB-C>Display Port because it was flakey with the HDMI connection previously.
Now it's the complete opposite.
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Reactions: george22


macrumors newbie
Oct 26, 2007
Same deal here - 2018 Mini.

The only way I can get the second monitor to function is to use HDMI.


macrumors newbie
Original poster
Oct 14, 2011
yea, i could only get it working via HDMI ... somebody said in another thread that DisplayPortVersion from the default v1.4 to v1.2 fixed the issue.

has anyone else tried this?

i am waiting for my mac studio to arrive this month, hope the problem goes away, as i'm adding one more monitor

Station Grey

macrumors member
Jun 18, 2020
This seems a strictly Mac Mini related issue, as my Mac Pro 5,1 works with all three 4K displays no problem.
Not at all. Many reports on MacBooks as well as iMacs.

It does seem to be limited to certain criteria though as it clearly isn't affecting everyone, and does seem more prevalent on certain machines, but because it works on one/your Mac Pro doesn't logically mean it only affects Minis!


macrumors regular
Mar 12, 2020
Not that it'll be any comfort to anyone experiencing this problem, but:

1. Ever since upgrading from MacOS 11 (which was a load of rubbish as far as I was concerned)
all 3 of the monitors connected to my 2018 Mac Mini have worked.

1.1. However, one of my monitors connects through an Apple USB-C to VGA converter which also has
a USB pass-through which is connected to a powered USB hub. If that hub is connected when the Mac Mini is booted
up that monitor stays bland: as soon as it is disconnected, the monitor display works, after which the hub can
be attached: very odd indeed.

2. But, oddly enough, 2 days after the release of MacOS 12.3.1 that update is not showing 'over here' in


macrumors 6502
Apr 11, 2019
Ontario, CA
Mine screwed up big time after the 12.3.1 update last night. I only have one monitor, a 28" Samsung 4K connected to a TB3 Sonnet 750ex GPU over Display Port. After the update finally finished, Mac rebooted to a black screen. Zapped PRAM a couple times, rebooted (by holding the power button in) several times, nothing.

After remembering about the reports of dead Thunderbolt graphics, I got out an HDMI cable and connected my monitor directly to the Mac. After that the monitor 'woke up' and switched on the DisplayPort finally, but my desktop was empty. Rebooted again after that and everything has been working so far. I dont know if plugging in the HDMI cable to the Mac itself (this is when the display kicked in) did it or what. I was so pissed after the update that whatever Apple did to fix everyone else's 2018 Mini broke mine that's been working perfectly hah. At least now its back.
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