After updating to Catalina, Mac Mini 2018 does not send any HDMI signal.
It was working fine today, until the Catalina update.
Can not enter safe mode nor recovery mode.
Tried resetting NVRAM, no change.
Just in case, I tried another cable and I also tried connecting it to AVR, but still no signal.
Mini is connected to 4K TV, I don’t have any other option (except USB-C to HDMI adapter which I don’t have).
Mac mini 2018 or later
cwanke72 mentioning lower res displays led me to workaround.
I dismissed it at first because I do not have any other displays except Sony 4K TV.
Then I remember Sony has two "30Hz non HDR" HDMI ports.
I connected Mac Mini to one of those, had to shutdown Mini (it was powered when I changed connection) and after I turned it on - signal was finally reaching TV.
Now I need to figure out how to make it work on 60Hz HDR port.
Have a Dell U2413 as a second screen connected via HDMI to Mac mini 2018. Worked fine with Mojave and initially with Catalina, now it's not being recognised. The screen says it is not getting a signal.
Thanks to everyone for sharing their experiences. On one hand, I'm glad it's not just me. On the other hand, I'm sorely disappointed in Apple. I moved away from Windows to avoid this kind of frustrating, time-consuming, and ultimately expensive issue. Catalina should not have been released without at least validating that it didn't break and advertised feature (HDMI) on the latest Mac Mini.
Anyhow, I had been considering getting an eGPU before and though it might be a way around this mess. I got a Sonnet Breakaway Box and an RX 570 card, supposedly a supported configuration. But all is not well on that front either. During boot, after the Apple logo, the monitor connected through eGPU goes solid white. A little Googling shows that this too is a common problem with Catalina. Apparently only the more expensive Vega cards are working smoothly at this point with Catalina. I'm waiting on one of those from Amazon.
Your assumption is that this is happening to EVERY Mac Mini. Every new iPhone release you hear about issues with activation, yet I’ve had nearly every version of the iPhone and I’ve never experienced activation issues. I’ve seen all kinds of issues reported through the years with Apple hardware I’ve owned and always wondered, “who are these people having these issues? I’ve never seen that with mine.” Well, here I am. First time in over 15years of owning Macs I’ve had anything but minor hardware issues. I doubt this effects every single Mac Mini out there. More than likely we all own Minis made on a particular day at a particular facility that did something oh so slightly different that caused this. Something Apple could have never caught without testing the new OS on tens of thousands of machines.
To break HDMI - there is no excuse, none.
We are paying A LOT for their hardware and the reason I do it - is quality assurance - both hardware and software.
Like someone said - this is not niche tech it’s freaking HDMI.
Either hardware QA failed or software did.
I refuse to pay that amount of money to be beta tester. I choose to beta test to see some updates early, but I except Apple to do high level QA for that money.
Otherwise - Linux and Huawei are far better choices.
I am using Acer KG241Q monitor to connect to Mac Mini 2018. During Mojave, it worked fine HDMI > HDMI. After upgraded to Catalina, HDMI > HDMI, USBC > HDMI > HDMI or USBC > DisplayPort did not work. I can't troubleshoot anything because there is no display to work with. I fear also that my SSD may crash as I forced shutdown it a number of times to try out the different ports. $&^$&$^ upgrade.
OK, so I too, have an LG UD2758-B and I tried your "temp solution"
which really is ALOT better than switching the hdmi cable to a low res monitor
to boot the mini and then switching back to the LG monitor
Now the funny part is, out of curiosity I enabled the option again and
shutdown/re opened the mini and picture is shown again.
BUT it's a pink color instead of black, and whole frame is shifted to the right ...
...until after I choose a user (i have 2 accounts on the mini) and then picture auto corrects it self.
Stranger and stranger things...
But thank u for discovering this, it beats having all the fuss of hdmi cable back and forth.
Given the issue is not resolved by rolling back to Mojave suggest it is firmware and not software.
given Apple have released a statement advising Mac mini users not to upgrade to Catalina they know what the issue is
The takeaway is that Apple upgrades cannot be trusted to be reliably developed. It's a short step from there to not buying their products. Machines which don't work cost money, time and patience. That adds up to a lack of goodwill towards a company which seems to have gone rogue in their quest for profit.
You have to pay? To test THEIR products... that they make a profit off of? You have to PAY to find their bugs?! Whelp, guess when my machine dies I'm headed back to windows. If I'm going to spend hours trouble shooting I won't be paying $1000+ for the machine I'm trouble shooting!
I'm not exactly sure what changed, but fiddling in Displays and going to AAA
explicitly seems to have turned things back on -- in any event, Built-In Retina
Display does not work even though I'm sure that did before.
My connection from the USB C port to HDMI worked fine under the previous operating system, Mojave. However, since I upgraded to Catalina on 20 October 2019 it has ceased to work. I see from posts on the Internet that this is a know fault. I wish to know when Apple proposes to release a bug fix to cure this fault.
Recently updated to macOS 10.15.1, display issue via hdmi persists
Anyone else still having issues after updating to macOS 10.15.1?
No luck here. Release notes for 10.15.1 didn't mention anything about a fix and people replying earlier using the beta version of 10.15.1 said it wouldn't address this issue. I was hoping they were wrong, but it looks like they were correct. Still no fix.
So sad that apple cannot handle his self-built current hardware with his current OS. I don‘t think it‘s exotic to connect a 4K-monitor through a built-in-hdmi-connector. So sad...
I want my current mac to get a current os.
Since I also reported success with the 10.15.1 update, I'll reply that my machine goes to sleep regularly and I have no problem 'waking' it, I continue to get a 4K output to my monitor with only the HDMI cable connected (I've removed the USB-C to HDMI adapter from my system). As reported previously I can also power down, and even unplug my mini and it still works.
However I'm sorry to hear that the 10.15.1 update isn't solving this problem for everyone, and we can't say what percentage it does fix as we only know who comes back to report here.
It certainly would be interesting to know what differentiates the monitors that still don't work, vs those that work with 10.15.1, vs possibly some that continued to work through the 10.15 upgrade (and never even knew there was a problem).
No HDMI signal after update
