Mac mini 2018 no display output over Thunderbolt after boot

Hello there,


I just bought a new Mac mini (2018 base model) and I'm having some trouble with my Thunderbolt 2 monitor (an LG 34UM95 Ultrawide connected via an Apple Thunderbolt (3 to 2) adapter & Thunderbolt 2 cable).


When I turn on my computer, I have no display output at all. Thus, forcing me to hold the power button on the Mac, after which it will launch the Recovery Assistant (where the display does work). After going through this procedure a few times, my Mac does finally boot to the login screen, for example, this time it worked when I pressed 'Restart' in the Recovery Assistant.


I have FileVault enabled and I'm running the latest version of Catalina at this time (10.15.2). I'm using a Magic mouse and Magic keyboard. Apart from this, the Mac mini has been working perfectly and I've had zero issues waking from standby etc - so I sort of think the issue could be related to the FileVault login screen.


Any suggestions?


Oh and of course, best wishes to all of you!

Mac mini, macOS 10.15

Posted on Dec 30, 2019 3:33 AM

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3 replies

Dec 30, 2019 7:04 AM in response to Navi98

Worth a shot but feel free to come back if it doesn’t work. IMO, nobody can’t tell between 50 and 60 Hz resolutions so HDMI is your one plan B. DisplayPort issues have a good chance of being resolved through monitor settings so that’s Plan B(b). Always on is plan C, just turn monitor off manually. To be honest, I can’t remember the last time I shut/restarted my mini. Except for updates it’s really as always-on as it gets, plus it runs super-quiet and whatever power savings lost, dkdc negligible.


To summarize, go for plans A, C, B(b) and B. Good luck!

Dec 30, 2019 5:48 AM in response to hcsitas

Thank you for your answer, however ditching TB2 is not really an option since the display only supports HDMI 1.4 (which limits me to 50Hz at the resolution of 3440x1440) and DisplayPort is plagued by even more issues (not waking from standby and the display showing a blank screen while it should be off after x minutes as defined in my Energy Saver settings). Also, the Thunderbolt connection allows me to change brightness and sound settings on my display, while the other inputs do not. Worst of all, the TB2 adapter and cable were €100 in total so I really want to make it work. When I used the display with my 2015 MacBook Pro with Thunderbolt 2 I encountered no issues, so this must be specific to this Mac.


Anyway, I'm gonna try disabling FileVault and see if this helps. Not ideal since I prefer encryption, but better than a Mac that doesn't boot nevertheless!


Cheers

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Mac mini 2018 no display output over Thunderbolt after boot

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