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User profile for user: kmckillop
kmckillop Author
User level: Level 1
9 points

Mac Mini 2018 - HDMI port will not wake

I have 3 monitors attached to my Mac Mini. 2 via USB-C ports and the 3rd via HDMI. On a regular basis, when my monitors go to sleep and attempt to wake everything up, the HDMI monitor will not wake.


The only solution to get the HDMI monitor to work is to shutdown (power down), unplug USB-C monitors and leave the 1 HDMI monitor plugged in and turn it back on. After that I can plug in the 2nd and 3rd USB-C monitors and life goes on. Until it happens again after going to sleep. This has gone on since I got it, sometimes it doesn't happen often, other times it happens very often, however I cannot 'make' it do this.


Unplugging the HDMI cable does nothing, the computer does not detect that the monitor is gone, in the display settings it still believes there is a 3rd monitor attached to the computer even after removing the HDMI cable.


If you power the machine down, and do NOT unplug the USB-C monitors, it will boot back up with NO HDMI again (while believing it is there).


The only way to reset this HDMI port is to remove the other USB-C monitors, power down and power on.


I've tried new OS resets this reset that, and nothing ever changes. I assumed after a year or two and 2 different operating systems this would be fixed by now, but it's not apparently?

Posted on Jan 11, 2021 3:27 PM

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User profile for user: Joseph_S.
Joseph_S.
User level: Community Specialist

Jan 13, 2021 1:58 PM in response to kmckillop

Hey kmckillop,


We're glad you thought to ask Apple Support Communities about the issue you're having with the display connected via HDMI after waking your Mac. You've provided some great details so far, and we appreciate that. If you haven't already, take a look at the following guide for some great steps to take: Get help with video issues on external displays connected to your Mac


If you have another HDMI cable to test with, that will help to rule out the current one causing the issue. We'll also want to see if this behavior continues while started to safe mode. This will help to know if a third-party process/app is causing this to happen. Here's more information on safe mode and how to start there: How to use safe mode on your Mac


You mention completing some resets. Did you reset the SMC and NVRAM? If not, let's do that now as those can help with this type of issue. Just in case, here's how:


How to reset the SMC of your Mac

Reset NVRAM or PRAM on your Mac


Keep us posted on the results.


Take care.

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Mac Mini 2018 - HDMI port will not wake

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