Mac Mini 2018 HDMI failes after OS upgrade / patch

[Fishrrman]

OP wrote:
"Got an email from Apple that there is no further information about this bug, that says still no fix date...."

Haha.
I predict you're going to be waiting a long time for that "fix".
A Long, LONG time.

 

[Adam Ellis]

Spoke to Apple again today after sending video proof of my work around which demonstrates that the port is too low voltage to operate reliably. They still claim it is running as it should and that my screens are not compatible with HDMI 2.0! I even bought Apple's own HDMI to DVI adaptor which didn't work reliably. Why do they make this adaptor if they are going to claim all screens need to support HDMI 2.0?! Unbelievable!

It worked fine until the security updates! They claim that they have implemented the correct protocol settings for HDMI 2.0 and it doesn't work with adaptors or HDMI 1.4!

Do any of you have your support case numbers for me to quote to prove that I'm not alone with this fault. They are saying it's not even a common issue and refuse to take it further. I've attached my evidence video of the 3rd party HDMI to VGA adaptor with auxiliary USB power boost. Clear proof that when the extra power is disconnected the Mac is confused what screens are attached.

I would love to publicise this online and even with the press. Any thoughts on this?

Thanks

Adam

 

[tstimper]

Do any of you have your support case numbers for me to quote to prove that I'm not alone with this fault. They are saying it's not even a common issue and refuse to take it further

my case was Executive RelationsCase: 101138355739
That case was opened on 2020-07-20 after i wrote an email to Tim Cook on 2020-07-16
After doing much hours of testing with an back line support engineer from Apple California
they confirmed about on 2020-09-07 that this is an bug in the graphics adapter firmware.
Its on their list to be fixed but still not fixed.
We got our money back directly from Apple on 2020-10-15 after they picked up the Mac mini 2018 on 2020-09-29

The real problem for us is that we cannot buy Mac mini devices until this is fixed...

I would love to publicise this online and even with the press. Any thoughts on this?

This is #macmini2018hdmigate ...
Share this ....

 

[Adam Ellis]

Thanks. I'll try quoting that reference with them to at least get them to admit the fault. How did you email Tim Cook by the way?

 

[tstimper]

How did you email Tim Cook by the way?

i found his email by asking Google : tcook@apple.com

 

[tstimper]

short update: i was able to get an refurbished Mac mini 2014 i7 16 GB Ram, very good condition.
Works with Catalina 10.15.7 without any problems with HDMI and Apple HDMI to DVI adapter and DVI monitor.
Same adapters and monitors which did not work on Mac mini 2018 after updating to Mojave 10.14.6.
It would be interesting if an M1 Mac mini has the same issue like the Mac mini 2018 or if it works like the Mac mini 2014 with HDMI and Apple HDMI to DVI adapter.

 

[djc6]

I found this teardown of an M1 mac mini:

M1 Mac Mini Logic Board

Explore this photo album by Brandon Geekabit on Flickr!

www.flickr.com

It contains the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter as the 2018 mac mini! My concern was now that a new mac mini exists, I wouldn't expect any firmware updates... but the M1 mac mini uses the same converter chip, so maybe a firmware update will come out for both machines. This is also the same chip used on the Apple TV 4K.

I no longer see this chip mentioned on MegaChips' website, but the M1 mac mini teardown does have a MegaChips logo on the chip. I now see the MCDP2900 series listed with another vendor kinet-ic:

MCDP2900 DisplayPort 1.4-to-HDMI 2.0 Converter

The MCDP2900 is an advanced DisplayPort1.4-to-HDMI2.0 protocol converter targeted for TVs, Game consoles and other consumer equipment.

www.kinet-ic.com

Data sheet has a Feb 2020 timestamp

 

[tstimper]

It contains the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter as the 2018 mac mini!

That would explain this: https://forums.macrumors.com/threads/mac-mini-m1-hdmi-to-dvi-issue.2270297/
New M1 Mac mini, same issue because of the same chip.
Can anybody confirm that a Mac mini M1 works with Apple HDMI to DVI adapter and a DVI monitor?
Which grafics adapter firmware do yo see on a M1 Mac mini?

 

[mdgm]

I'd like to get the Mac Mini 2018, but as I would use it as HTPC the HDMI working is essential for me.

 

[tstimper]

I'd like to get the Mac Mini 2018, but as I would use it as HTPC the HDMI working is essential for me.

I like the Mac mini 2018 because of the 64 GB option. But HDMI to DVI is essential for me. I contacted the Apple representive i was working on the issue to get an update when the fix will be available. Now that we know that the Mac mini M1 internally use the same MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 chip there should be a solution soon.

 

[harriska2]

I can't find anyone that uses the Thunderbolt port on the 2018 mini to an HDMI 2.0 port on a monitor. My monitor only has HDMI and I'm not willing to give it up.

 

[djc6]

I can't find anyone that uses the Thunderbolt port on the 2018 mini to an HDMI 2.0 port on a monitor. My monitor only has HDMI and I'm not willing to give it up.

I do; I use this Thunderbolt to HDMI 2.0 cable so I can get 4K @ 60Hz:

Cable Matters USB C to HDMI Cable, Supporting 4K 60Hz (USB-C to HDMI Cable) in Black 6 ft - Thunderbolt 4 / USB4 Compatible with iPhone 15 Pro Max Plus, MacBook Pro, Dell XPS 13, Surface Pro and More

Cable Matters USB C to HDMI Cable, Supporting 4K 60Hz (USB-C to HDMI Cable) in Black 6 ft - Thunderbolt 4 / USB4 Compatible with iPhone 15 Pro Max Plus, MacBook Pro, Dell XPS 13, Surface Pro and More

smile.amazon.com

"Cable Matters USB C to HDMI Cable (USB-C to HDMI Cable) Supporting 4K 60Hz in Black 6 ft - Thunderbolt 3 Port Compatible with MacBook Pro, Dell XPS 13, HP Spectre x360, Surface Pro and More"

 

[harriska2]

I do; I use this Thunderbolt to HDMI 2.0 cable so I can get 4K @ 60Hz:

Cable Matters USB C to HDMI Cable, Supporting 4K 60Hz (USB-C to HDMI Cable) in Black 6 ft - Thunderbolt 4 / USB4 Compatible with iPhone 15 Pro Max Plus, MacBook Pro, Dell XPS 13, Surface Pro and More

Cable Matters USB C to HDMI Cable, Supporting 4K 60Hz (USB-C to HDMI Cable) in Black 6 ft - Thunderbolt 4 / USB4 Compatible with iPhone 15 Pro Max Plus, MacBook Pro, Dell XPS 13, Surface Pro and More

smile.amazon.com

"Cable Matters USB C to HDMI Cable (USB-C to HDMI Cable) Supporting 4K 60Hz in Black 6 ft - Thunderbolt 3 Port Compatible with MacBook Pro, Dell XPS 13, HP Spectre x360, Surface Pro and More"

Are you on Big Sur with the mac mini (2018)?

 

[tstimper]

Are you on Big Sur with the mac mini (2018)?

My last test with Mac mini 2018 was with latest Big Sur beta. That did not fix he issue.
Big Sur works without any HDMI to DVI adapter issues on Mac mini 2014.

 

[djc6]

Are you on Big Sur with the mac mini (2018)?

No, I've used the Cable Matters USB-C to HDMI 2.0 6ft cable with Mojave and Catalina. I haven't found a compelling reason to upgrade to Big Sur, and I usually wait for a couple point releases anyways.

 

[manofheck]

I have this issue with 4K monitor only. Happens in Catalina and Big Sur. I have a three monitor situation with two 1080p and one 4K; and only the 4K is impacted. Doesn't matter if it is on the HDMI port or on a TB3 port with TB3 compatible to HDMI cable. My work around is to use one of the 1080p monitors as the primary, watch the ASUS 4K monitor struggle to get a sync signal for about 30 seconds, and if it fails - PDPU. I have it on a smart switch so I can voice command it . Usually syncs right away at this point. This occurs on first boot and after a sleep cycle.

 

[normd1954]

This is #macmini2018hdmigate ...

Mac Mini 2018 -> no HDMI after OS Upgrade is a known problem.
Apple support confirmed to me today that they know that and are working on a solution.

The problem started with Mojave 10.14.6. The only permanent solution today is to go back and stay on Mojave 10.14.5 on Mac mini 2018 as long as Apple is able to fix this.

My Mac mini 2018 has now the third logicboard. The new logicboard always came with Mojave and it broke after upgrading to Catalina.

I got my Mac mini 2018 back from Apple partner yesterday. Mojave was on it and HDMI was working.
Then i have started internet recovery to install Catalina 10.15.2 and HDMI was still working.

Today i upgraded to Catalina 10.15.3 and the #macmini2018hdmigate is back again.

After all this trouble with two logicboard replacements and support chats and support calls
i found, that the SECOND update on a fresh logicboard breaks HDMI on a Mac mini 2018.

Example one:

New mac Mini 2018 with Mojave 10.14.5 -> HDMI ok
Update to 10.14.6 -> HDMI ok
Update to 10.14.6 supplemental update -> HDMI fail

Example two:

New logicboard in Mac mini 2018 with Mojave 10.14.6 -> HDMI ok
Internet Recovery -> install Catalina 10.15.1 -> HDMI ok
Update to Catalina 10.15.2 -> HDMI fail

Example three:

New logicboard in Mac mini 2018 with Mojave 10.14.6 -> HDMI ok
Internet Recovery -> install Catalina 10.15.2 -> HDMI ok
Update to Catalina 10.15.3 -> HDMI fail

SMC reset does not help.

Thunderbolt display is always working, but i have none to test.

Anybody else see this behavior?

I had a simiar problem with why Samsung. Had to keep resetting the input form HDMI > something else . HDMI. Very frustrating. Ended up upgrading to a MacBook Pro and the Samsung works OK, but slow to wake.

 

[macfix17]

It seems Big Sur fixes this issue (looong after it should have been addressed):

Big Sur 11.2:
macOS Big Sur‌ 11.2 improves Bluetooth reliability and fixes the following issues:
- External displays may show a black screen when connected to a ‌Mac mini‌ (‌M1‌, 2020) using an HDMI to DVI converter

Could any of you using Big Sur 11.2 confirm this works?

 

[Janeilfen]

I don’t know if this is the same issue that I and some others have, where the monitor screen goes blank for a few seconds, on a random basis? But if it is related and the comment from djc6 that “It contains the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter as the 2018 mac mini!” is true then I was not impressed with Apple support this morning. They told me that they were unaware of any such issue. I have now installed 11.2 on my 2018 Mac mini to see if it cures my problem.

 

[macfix17]

Let us know if it fixes it!

 

[Janeilfen]

I will. I’ll see how it goes over the next few days.

 

[harriska2]

I don’t know if this is the same issue that I and some others have, where the monitor screen goes blank for a few seconds, on a random basis? But if it is related and the comment from djc6 that “It contains the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter as the 2018 mac mini!” is true then I was not impressed with Apple support this morning. They told me that they were unaware of any such issue. I have now installed 11.2 on my 2018 Mac mini to see if it cures my problem.

Well now, that’s interesting. I have that problem, too. Happens about every 10-20 hours of being on the computer. It does affect my zoom calls, which is a pita. But it comes back all ok. Just very annoying. Will not get another mini if this type of behavior persists. Will *never* buy an all in one imac as I use a 40” 4k monitor. And no way can I afford a pro. Hope they don’t make me go back to Windows ....

 

[tstimper]

It seems Big Sur fixes this issue (looong after it should have been addressed):

Big Sur 11.2:
macOS Big Sur‌ 11.2 improves Bluetooth reliability and fixes the following issues:
- External displays may show a black screen when connected to a ‌Mac mini‌ (‌M1‌, 2020) using an HDMI to DVI converter

Finally the confirmation in an official Apple document that the problem with black screen using an HDMI to DVI adapter exists. And that there is a now a fix after 560 days. July 22, 2019 - February 1, 2021
Can someone confirm that the fix works with the Mac Mini 2018 (2020) Intel?
And did the last security update for Catalina and Mojave fix this as well?

 

[macfix17]

Good question - will we be able to have it fixed with Catalina (or Mojave) after we have been stuck with the problem for almost 2 YEARS?

The latest Catalina update does not fix anything.

 

[Janeilfen]

Let us know if it fixes it!

So far it's been OK. No more black screen issues at all. I have now installed 11.2.1 First thing I noticed was that I do still have bluetooth problems with my Version 1 trackpad. Not bad but annoying. Bear in mind that my setup is quite basic. 2018 Mini with quite old U2312HM monitor. Logitech bluetooth keyboard and my version 1 trackpad.