HDMI Port No Longer Working After Update to macOS 11 Big Sur

[theunk]

11.5 update applied. On restart the default display was the Thunderbolt connected LG. It powered it off, the HDMI connected Dell came on. I powered the LG back on, the screens shuddered a few times and now all is well.
Hope it continues.

To be clear my mini is working very well. Just reporting on what I observed as it configured the video output.
I am continually impressed with how this i3-8GB-128GB performs.

 

[secretanchitman]

Sorry to hear that you all are still having issues with HDMI - 11.5 is working great still on my Mac Mini!

 

[theunk]

Sorry to hear that you all are still having issues with HDMI - 11.5 is working great still on my Mac Mini!

My report may have confused. I edited it to be more clear.

 

[secretanchitman]

macOS 11.6 released today, happy to report that HDMI still works great on my 2018 Mac Mini!

 

[theunk]

macOS 11.6 released today, happy to report that HDMI still works great on my 2018 Mac Mini!

Same here. ?

 

[theunk]

For some time now I have used only a single display. This morning I was in a GoToMeeting and turned on my second monitor that is connected Thunderbolt > HDMI. Both displays were cycling on/off to to the point I powered off the TB >HDMI display. Today I got a software update nag for the Safari 15 update. I installed it and now the TB>HDMI connection is dead.
HDMI still works.

 

[t0pher]

I never had this issue with 11, I've just "upgraded" to macOS 12 beta 8 and I can no longer usb-c -> hdmi to my LG 4k screen. tried the usual steps and no improvement. the usb-c-hdmi cable works fine in my Lenovo t13 (first time I've used the cable in that machine).

I've tried a usb-c hub to hdmi etc and still no joy

airplay works though but is so laggy.

 

[theunk]

I have updated to Monterey 12.0.1 and have dual monitors, 1 HDMI>HDMI and one TB3>HDMI
So far 24 hours stable.
?

 

[pwang42]

I upgraded to Montery 12.0.1.
HDMI works again... but only if it's the only display connected at boot time. Once it's fully booted, I can add another display on TB3. Otherwise, the HDMI may or may not be detected, but either way the monitor will remain full dark (no signal detected by the monitor).

Also, my bluetooth is now broken. (actually, bluetooth works when macOS isn't loaded yet, so the hardware isn't burnt...)

 

[theunk]

I upgraded to Montery 12.0.1.
HDMI works again... but only if it's the only display connected at boot time. Once it's fully booted, I can add another display on TB3. Otherwise, the HDMI may or may not be detected, but either way the monitor will remain full dark (no signal detected by the monitor).

Also, my bluetooth is now broken. (actually, bluetooth works when macOS isn't loaded yet, so the hardware isn't burnt...)

I had the same experience. I have a TB3 to @X HDMI splitter that I tried. It would not support both displays. The only way to undo was to connect the Dell monitor back to HDMI, reboot, then connect the LG via TB3 > HDMI. My Bluetooth is ok so far. I did experience the odd time when the Magic Mouse mouse loose connection, but since Monterey I have not experienced.

 

[pwang42]

Still 12.0.1 (21A559) but bluetooth works... 2 weeks later (no reboot). It would seem that bluetooth kind of works now. I haven't used my mac mini for 2 weeks but I haven't rebooted it either, and now it bluetooth is activated and 2 devices are connected! And the work! I've just unplugged the keyboard and the trackpad, they still work. Buggy bluetooth, but at least it's back! I have no idea why it took at least hours (if not days) for macOS to turn the bluetooth on.

 

[MylesTheGray]

2018 Intel Mac Mini. Same issue.

Hdmi port will not work correctly.

However, using adapters seems to work just fine.

 

[allejo]

Reporting in from an Intel 2018 Mac Mini running Monterey 12.1 and my HDMI port isn't working. When I boot in safe mode and have only my HDMI port connected, the display works but when I boot regularly, having a single HDMI monitor doesn't work.

 

[secretanchitman]

HDMI port still works fine on my 2018 Mac Mini after updating from 11.6.1 to 12.1!

 

[Turribeach]

So I am going to add my experience as I think it might help other people too. Like most on this thread I have a MacMini 2018 with two identical 27" Dell 1440p monitors, one connected via USB Type C to DP cable and the other over HDMI to HDMI. I have been running Mojave with this setup since 2018 for nearly 4 years and not had issues on my Mac recognising the HDMI monitor AFTER I did the initial setup. I do remember having to play around with lots of cables and different configurations until I got both monitors working with one over HDMI, but I can't remember the specifics. I do want to connect the second monitor over HDMI since I use all the other Thunderbolt ports for other devices. Recently I upgraded to Monterrey 12.2 and after the upgrade I had two incidents where the monitor connected over HDMI failed to be detected.

How I fixed it the first time: I added a second cable to the HDMI monitor using a USB Type C to DP cable (leaving the HDMI cable connected) and after a few tries of plugging and unplugging things it worked. I removed the USB Type C to DP cable and it continued to work over HDMI.

Today it happened again and the first method did not work. This time I tried NVRAM/PRAM reset until it worked. Please note that for years I haven't been able to do a NVRAM/PRAM reset because Apple forgot to tell users that if you have a firmware password (which I always did) you must disable the firmware password before you can perform a NVRAM/PRAM reset. Apple have now updated their support page but thank you Apple for wasting hours of my time over the years failing to do NVRAM/PRAM reset trying to fix other issues. For all the good design and UI that Apple does all this NVRAM/PRAM, SMC, etc is such an infuriating and inconsistent mess. Why can't it just work? So make sure you perform the NVRAM/PRAM reset correctly. On a MacMini 2018 you need to press Command+Option+P+R. You should hear the Mac chime twice and see the Apple logo twice. You can release the keys after the second startup sound or Apple Logo if your Mac doesn't chime.

OK and here are a few tidbits of information based on my tests and experience with this issue:

1. It's 100% a software issue, the fact people keep seeing this issue come and go with different OS versions proves it
2. To support my theory I can 100% make the HDMI monitor work if I boot with the HDMI monitor as the ONLY monitor. But if I plug the second USB Type C monitor after the MacMini booted with the HDMI it doesn't detect it. If I reboot having both, it will fall back to the USB Type C monitor working and the HDMI monitor will not work
3. I never power off my Mac since it runs some home automation processes, so even though I didn't reboot my Mac I had the issue happening only after the monitors turned off due to screen turned off due to inactivity. So again this points to a software problem since the hardware is working perfectly and did not change, just monitors turned off and back on!
4. Another evidence pointing a software problem is that my HDMI monitor flicks when I reconnect the HDMI cable to the MacMini while the Mac is booted and the HDMI monitor is not detecrted. It then seems to try to connect and displays the "No HDMI signal detected" error. So again this points to an HDMI sync issue aka a software problem!
5. When the Mac boots properly with two screens you can see the second monitor is on BEFORE you login (ie the second monitor will show your chosen desktop wallpaper). I decided to perform a cycle of NVRAM/PRAM reset and LOGIN multiple times to see it would help. The HDMI port worked after the third NVRAM/PRAM reset + Login retry. I don't know if there is any relevance to my procedure but I hope that it might be something into this process that helps. Give it a go and post back if it helps you!

Finally if I had to throw any money at where the problem is I would think it's a HDMI sync issue most likely due to HDCP, the encryption protocol used in HDMI. If anyone is experiencing the problem as has a HDCP stripper/HDMI splitter/HDCP Bypass it will be great if you can test adding one of those to your HDMI monitor to see if it helps. I will buy one to test but I will have to wait for the issue to happen again to see if it works. Can't wait, this causes me so much love for Apple...

 

[gusping]

Nearly 2 years later and the issue has not been fixed. Unbelievable. Good job Apple. The issues I’ve had with my mini is endless.

 

[MylesTheGray]

Thanks god they didn’t drop the Intel Mac mini completely from its new line of mini’s. Atleast we know it will be supported for quite some l.

Apple products used work so well and usually there very few hiccups. It’s appears apple is now trying to compete with other operating systems in terms of features.

We just want the computers to work well and to work well for a long time.

My next music rig will probably be Linux based.

 

[allejo]

I can't freaking believe it... I really hope I don't jinx this for myself but disabling "Deep Color" on the monitor that is connected via HDMI solved the problem for me.

Update: It fails occasionally still, at which point if I reset my monitor to factory settings and disable Deep Color again, it just magically works...? I don't even know anymore.