I have a 6 month old Mac Mini (2018) recently upgraded to Catalina. I use dual displays (HDMI port and Thunderbolt HDMI adapter) and now every time the Mac goes to sleep the HDMI port stops working. Only a full shut down and restart fixes the problem (a regular reboot does not).
I tried switching cables and swapping monitors, did not help.
Anyone else having this? Hopefully Apple is aware and can fix it.
Mac mini 2018 or later
I think I have fixed this for anyone else who may have the issue. I am now using two high speed HDMI cables for each monitor and the issue hasn't come back. My monitors are basic 24" HD monitors, nothing special, so I didn't think a high speed HDMI would be necessary (it wasn't previously). It's only been a few days but fingers crossed this is it.
I think I have fixed this for anyone else who may have the issue. I am now using two high speed HDMI cables for each monitor and the issue hasn't come back. My monitors are basic 24" HD monitors, nothing special, so I didn't think a high speed HDMI would be necessary (it wasn't previously). It's only been a few days but fingers crossed this is it.
I reported to Apple but decided to try a full wipe and re-install of Catalina to see if it helps. Not something I should have to do but it is something I like to do periodically to keep things clean, so something I'm used to doing. It's installing again now (install failed the first time) so will see how it goes.
That said although I'm a long time Apple user I only made the switch of my home desktop computer from Windows (custom build PC) to Mac for the first time 6 months ago because I was tired of spending time diagnosing dumb driver issues and odd behaviour. I wanted something usable and stable. Although I like macOS, it hasn't been as stable as I had hoped.
So after a full system wipe and fresh install of Catalina (well not entirely fresh, I was forced to put on Mojave and then upgrade, long and painful story...), the issue is back. I didn't do a restore at all, everything was a fresh install.
I thought it was gone after a day or so and both monitors were still responding but alas today I woke up the computer and the HDMI port appears to be dead again.
The other odd thing that happens is when the Mac starts up, for the first 10s or so of the startup screen (Apple logo) the screen is purple. Once the logon screen appears the colours are back to normal. I also see this after sleep, the screen sometimes goes purple or shows static for a few seconds before fixing itself. That is when it's working, today it just stayed off.
Next I'm going to start removing apps and see if one of those is the culprit, grasping at straws though.
After discussing with Apple support this is apparently a known issue and being worked on to patch in a future update. In the meantime a workaround is to use two USB-C Thunderbolt HDMI adapters, which I am now doing.
Something which has worked for me a few times now. I use a usbc to hdmi adaptor. I unplug the hdmi from the adaptor. Plugin the adaptor and then plug in the HDMI cable. That seems to have worked several times for me now. If I leave the HDMI plugged in when I plug the adaptor in I get the same thing everyone else is complaining about.
1) Catalina Version 10.15.1 still has HDMI port issues on Mac Mini (2018). Sometimes the HDMI port works, and sometimes it doesn't. Sometimes the monitor works with a thunderbolt to HDMI adapter, sometimes it doesn't. It seems that each morning I have to spend several minutes manually rebooting my mac mini 2-4 times before I get the restart screen. Before that my monitor is blank. I've tried several different monitors and HDMI cables, and the problem remains the same. Thus it appears to be an issue with the mac mini, and I didn't have the issue prior to the Catalina upgrade. Thus, either it's Catalina 10.15.1 (still no better) or it's a bad HDMI port on the mac mini (but I don't think so b/c it's the same issue when connecting the monitor to the mac mini via a thunderbolt to HDMI adapter.
2) Amazon prime music now no longer plays music/works with Catalina.
Apple, please promptly address these fundamental issues noted above. Thank you in advance for your time and efforts.
I have a late 2012 Mac mini I got 2nd hand that came with Mac OS Mountain Lion and worked just fine with my old Sony TV that has a single hdmi port. After updating to Catalina, I could no longer control the overscan of the tv monitor. I went back to Mt Lion and found that the underscan slider in the monitor’s preferences is missing in all later MacOSs. As far as Mojave, there are 2 available presets that deal with the overscan problem but they don’t take hold on start up. They can only be selected from system preferences after bootup by reaching the preferences panel in the menu bar which is completely off screen. And when the screen is not busy, it reverts to tv overscan and the monitor has to be reset again from the preferences panel. In Catalina there are no presets to choose from and there is no underscan slider. Why were they removed? Can’t afford to buy a new tv.
Make sure you report your issue here:
You may also want to contact Apple Support directly:
Same problem here. Fun fact, booting with eGpu ... also no signal. At this point Catalina basically made my expensive system useless and I’m a little tired of Apples buggy hard- and software.
Nope, not solved. The issue is back even with the high quality, high speed HDMI cables. I give up!
Try using a 60Hz cable. Same thing happened to me after the catalina update, I switched my 30Hz cable to a 60Hz and presto, works the same.
Catalina upgrade - HDMI stops working on Mac Mini (2018)
