Catalina causing issues with HDMI

LeeW

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Original poster
Feb 5, 2017
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Glasgow, Scotland
Just for those that are having issues with HDMI - HDMI video connections after upgrading to Catalina, eventually managed to get beyond basic support level and spoke to someone who appeared way more knowledgeable.

Many are having issues getting a basic HDMI connection to work at all or only through weird and wonderful workarounds. Apple has confirmed to me they are aware of the issue and they advised it was an issue they could replicate when using HDMI -> HDMI.

Of course, no information as to when this may get fixed.

For most, the answer is to use USB-C to HDMI or DP but it is not assured to work but seems to in many cases.

For those that are going to revert back to Mojave as a solution, a number of people are noting that this does not fix the issue (it didn't for me), indicating there is perhaps some sort of firmware update taking place with Catalina that will not be rolled back when you install Mojave.

The most affected users from what I have seen are those using 4k displays, it makes no difference what cable is used they can only get back up and running by connecting to a lower resolution monitor.

So just a warning really, add any updates if you have them but it is clearly is an issue and I suspect won't get resolved swiftly.
 
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weaztek

macrumors regular
Aug 28, 2009
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Twice when I had to "computer voodoo jump start" my HDMI (LG 32" 4k) monitor connection I got an Out Of Range warning on my LG. After looking that up, it's apparently an error for the monitor running at an unsupported resolution. Mine is at 3008x1692 so, not one of the default resolutions. I wonder if I should change it to a standard res?

I also set my Energy Saver to "Never" turn display off in case that setting was causing the permanent sleep issue.
 

LeeW

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Original poster
Feb 5, 2017
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Glasgow, Scotland
I had replied to you on the other thread, but even after reinstalling Mojave the issue remained so it does appear to be something beyond Catalina alone, i.e. firmware that is not being rolled back with the OS.

But the issues people are experiencing are so wide-ranging there is nothing to pin-point as the definite cause, yet.
 

kaibob

macrumors regular
Jun 21, 2010
231
62
Prescott, Arizona
I figured installing Catalina was safe because I had several reliable backups that would take me back to Mojave. Unfortunately, my 4K monitor (hdmi to hdmi) didn't work under Catalina and continued not to work after going back to Mojave. So, I figured it had to be firmware or something similar.

Fortunately, a DP to USB-C cable got my monitor working and I'm avoiding Catalina like the plague.
 
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weaztek

macrumors regular
Aug 28, 2009
124
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I just ordered a Warrky USB-C to DisplayPort cable from amazon.

I'm looking on the bright side. Apple [mostly] figured out the Mac Mini wake from sleep woes in the last version of Mojave and I think they'll roll out some fixes quickly.

Frankly, since I have the latest-gen Mac I fully expect to be able to keep it up to date on Catalina. I just hope they roll out the Catalina fixes this week.
 
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LeeW

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Original poster
Feb 5, 2017
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Glasgow, Scotland
So, I figured it had to be firmware or something similar.
It is looking more and more likely as the suspect.
- - Post merged: - -

I just ordered a Warrky USB-C to DisplayPort cable from amazon.
USB-C to DP is working perfectly for me and there is no issue so far with waking so I agree, thats something, but you know, break something to fix something :)
 

Queru

macrumors newbie
Jul 29, 2019
21
12
Good to know. I’m Using my Mac mini with eGPU and 4K display with no problem but in Windows instead of MacOS - it’s the only way to reliably use this device now. Thank you for letting us know.
 
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Fishrrman

macrumors P6
Feb 20, 2009
17,442
5,653
I have a 2018 Mini i7 connected to a Viewsonic 27" 1080p display (2770).
Display is connected with an HDMI (Mini end) to DVI (display end) cable.

My internal drive has Mojave on it.
I have an external SSD with a copy of Catalina on it.

Both OS's exhibit the same behavior re the display. That is:
1. Display ALWAYS "goes black" during the boot sequence,
but
2. Display ALWAYS "comes back on" after being dark a second or two.
 
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weaztek

macrumors regular
Aug 28, 2009
124
35
Also having this issue. HDMI connection to LG 4K TV no longer works.
A user in another thread resolved that issue this way:

The fix that worked for me is to change a setting in the TV. Toggle ON the setting for HDMI Ultra HD Deep Color, it’s found in advanced Picture settings of the tv.[/
- - Post merged: - -

 

Partron22

macrumors 68020
Apr 13, 2011
2,498
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Yes
Anyone know if there's a thread here, or another site describing how to revert firmware?
Will reinstalling the original OS that came with the Mac do it, or do we have to go digging for an old "firmware update" file of the type Apple used to release with warnings attached? Not sure even that'd do it. Perhaps "old Mac" sites have collections of day one firmware installers through the years?
This issue could prove quite troublesome.
 

LeeW

macrumors 6502a
Original poster
Feb 5, 2017
933
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Glasgow, Scotland
This issue could prove quite troublesome.
Probably that ^^ unless you know exactly what has changed. If reverting back to Mojave does not fix it then no version will. Apple are not giving out any more info, probably trying to get a fix out before admitting anything was wrong other than advising not to upgrade at this time.

The only real workaround at this time appears to be using USB-C to HDMI. Older cables don't seem to fix it though, needs to be a reasonably new one.
 
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TopherMan12

macrumors 6502
Oct 10, 2019
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Atlanta, GA
I guess I'm lucky. I have one monitor connected via HDMI -> HDMI and another connected USB-C -> HDMI. Did not have a problem before or after upgrading to Catalina.
 
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LeeW

macrumors 6502a
Original poster
Feb 5, 2017
933
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Glasgow, Scotland
I guess I'm lucky. I have one monitor connected via HDMI -> HDMI and another connected USB-C -> HDMI. Did not have a problem before or after upgrading to Catalina.
Quite a few have noted that this is the one configuration that can work, it seems to be that one connected using USB-C to HDMI somehow kicks the HDMI -> HDMI into action.
 

hagjohn

macrumors 6502a
Aug 27, 2006
644
494
Pennsylvania
I have USB C (Mini) -> USB C In (eGPU) -> DP Out (eGPU) -> DP (LG 4K Monitor). Now I get the white screen when booting to eGPU but when I have HDMI (Mini) to HDMI (Monitor), it seems to boot fine. I then switch it over to eGPU, so I do not leave HDMI on.
 

mcnallym

macrumors 6502a
Oct 28, 2008
713
220
Using mine headless with a fit 4K headless display and running 1080p on it. No actual monitor attached but working fine for me.
will be interesting to see how fixed.
hackintosh also upgraded to Catalina without issue so far very happy on catalina.
upgraded on the 10th after opendns released a 64 bit updated, as that was all holding back.
so far not seen any issues with Catalina but I only access via screen sharing
 

Easttime

macrumors 6502a
Jun 17, 2015
569
384
I did not know about this before I installed Catalina. Mac mini 2018, all is running fine. Two monitors: One 27" USB-C, the other 27" HDMI. Both "2.5K" types. Both OK. Sometimes the HDMI monitor does not wake from sleep, but that started before Catalina, and I bring it back by just turning it off then on. Same with my Magic Trackpad hard wire connected to the mini, and that also began before Catalina.
 

shinji

macrumors 65816
Mar 18, 2007
1,309
1,499
I'm not having this issue with a P2415Q connected HDMI->HDMI. Also have an Apple Cinema Display connected via DVI->USB-C.

But my displays never sleep no matter what Energy Saver settings I use.
 

Partron22

macrumors 68020
Apr 13, 2011
2,498
711
Yes
Number of public Betas Catalina went through, you'd think someone would have noticed and reported the problem. Apple's QC dept. must be heavily de-emphasized compared to a decade ago.
Or maybe they just want this to be the last Mini.
 

LogicalVue

macrumors member
Aug 28, 2007
84
47
USA (Maine)
Yesterday I installed Catalina on my Mac mini 2018 on an external USB3 SSD without trouble. I had previously been running the betas, also without trouble. I'm using a 4K display connected with a USB-C to DisplayPort cable.

Unplugging the external drive and booting back into Mojave also worked fine.
 
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weaztek

macrumors regular
Aug 28, 2009
124
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Which is a shame because the fix requires one of the USB ports. I'm getting low on those again.