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Confirmed exact same issue for me as well. Just got my M1 Mac Mini today. I've tried both a DVI cable with an HDMI adapter, as well as a straight HDMI to DVI cable, with two different monitors. On one monitor I get static, on the other I get "this format is not supported".

Thankfully I bought a USB-C hub that includes an HDMI output port, and the monitors work when I plug them into that port.

Would be great if they could roll out a software update that fixes this, but until then it looks like I'm buying another USB-C adapter, because I need 2 monitors for my job.

I don't think that will work. With the current M1 Mac mini it only supports two Monitors and one of them has to be connected via HDMI. I already tried using another USB-C adapter with mine and that did not work.
 
I've got an old Westinghouse 1440x900 19" and this is what I get with HDMI->DVI-D on my M1. Works fine on my old Mac. Works fine with a USB-C to DVI-D adapter. Tried different resolutions and same thing.

4DB893A9-4C9B-41F6-915D-0C6FCEC27123_1_105_c.jpeg
 
@saulinpa : This is exactly what I see on one of the two HP display, the other one just stays plain black.

I investigated a but further and there is the idea that the HDMI out of the Mac Mini M1 has "HDCP enabled" per default and it cannot be turned off (or it doesn't turn off for non compliant displays).
My displays don't understand HDCP as they are too old, so this might be it.

... that would also explain why the issue happens independently from the cables being used.

I will try one last thing ..... I ordered an HDMI splitter which should "remove the HDCP from the video signal".
For PS4 users this did the trick according to the reviews.

It would be a bit a clumsy solution but temporarily acceptable. I expect Apple will get this fixed as they advertise DVI out via HDMI (and not stating that the display needs to be HDCP compatible). But these might also be false hopes.

The device will arrive Tuesday and I'll report back once tested.
 
I don't think that will work. With the current M1 Mac mini it only supports two Monitors and one of them has to be connected via HDMI. I already tried using another USB-C adapter with mine and that did not work.
Funny, I just hopped back on here to inform everyone that, as you said, this doesn't work, haha. Didn't realize that to use two monitors, one has to be in the HDMI port and the other has to be in one of the USB-Cs.

Oh well, guess I'm living with 1 monitor until I get an HDMI display.
 
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Interesting info and possible workaround.
Could you elaborate on this a bit further (USB-C Hub model and setup).

You are driving both monitors via the hub then or one from the Mac's genuine USB-C Port (via USB-C -> DVI Cable) and the other monitor via the hub?

(My displays are old but trusted and there is currently no strong reason for new ones.
..... well they are not that bright anymore I suppose bit still crisp.)

Sorry I should have been more specific. The USB-C "hub" I was talking about only has 1 HDMI output on it. The rest of the ports are USB3 ports.

Regardless, my plan didn't work. I was hoping that I could plug one monitor into each USB-C port via an adapter/hub, but turns out you can only use one of those at a time for display.

So no, at the moment I'm still only able to run a single monitor. I think the only option is to get a proper HDMI display so that no DVI is cable is needed. Then you run that monitor directly to the HDMI port on the Mac Mini, and the other to one of the USB-C ports.
 
I've had a couple of problems hooking my M1 up to monitors via USB hubs.

The straight HDMI out always works.

However, HDMI via a USB-C hub seems to depend on the vendor. I have two hubs, one HooToo and one Anker, two different WQHD monitors (Acer, HP), and a Samsung 1080p.

The internal HDMI will always drive the WQHD monitor fine.

The 1080P (HDMI -> DVI) works with the HooToo hub, not the Anker. On the Anker the picture is distorted.

For the WQHD monitors, the HP won't work with either hub; it's HDMI->DVI. The Acer monitor won't work with the Anker, but works with the HooToo - except the picture goes in and out.

So basically, the Anker HDMI port is pretty useless. The HooToo works, but also has issues with > 1080P. Anker is going back to amazon. I suppose it's time for a real TB3 port.
 
I am facing the same problem enumerated here, with the additional issue that I have not even had a chance to set the Mini up: I turned the danged thing on with my old HP display connected via a convertor and was greeted with a wall of static and "Signal Out of Range" before I could even enter a language! This is immensely vexing, particularly as I'd just upgraded from an ancient Power Mac (yes, really) whose power supply had finally given up the ghost and decided to go with something more modern aside from the iPad I'm typing this on.

Did I waste my money on the HDMI-to-DVI-D convertor? Should I run this through the VGA port or something? I don't think I even have a VGA cable, let alone an adaptor. And if there will be an update to fix this, would I have to bring the Mini in to instal it? It's causing me quite a bit of anxiety, frankly; I'm not exactly well-off, and this was a bit of a splurge…

Edit: I've calmed down a bit and realised I just need a USB-C adaptor until the fix is made, but I'm still pretty exasperated. Just, bluh.
 
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I am facing the same problem enumerated here, with the additional issue that I have not even had a chance to set the Mini up: I turned the danged thing on with my old HP display connected via a convertor and was greeted with a wall of static and "Signal Out of Range" before I could even enter a language! This is immensely vexing, particularly as I'd just upgraded from an ancient Power Mac (yes, really) whose power supply had finally given up the ghost and decided to go with something more modern aside from the iPad I'm typing this on.

Did I waste my money on the HDMI-to-DVI-D convertor? Should I run this through the VGA port or something? I don't think I even have a VGA cable, let alone an adaptor. And if there will be an update to fix this, would I have to bring the Mini in to instal it? It's causing me quite a bit of anxiety, frankly; I'm not exactly well-off, and this was a bit of a splurge…

Edit: I've calmed down a bit and realised I just need a USB-C adaptor until the fix is made, but I'm still pretty exasperated. Just, bluh.
It is a quite basic issue that is broken. Even with the 11.1 update it is still bad. Let's hope it is fixable in software/firmware and not a hardware issue. It is corrupted in boot selector/recovery mode so I don't have much hope.
 
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I've had good luck with this cable, I wonder if its wired any differently than an HDMI to DVI converter:

 
I've had good luck with this cable, I wonder if its wired any differently than an HDMI to DVI converter:


@djc6

Can I ask what "had good luck with this cable" means? Kindly elaborate a bit on that.

You know .... it could just be that your display offers the required properties. In that case most cables would have worked.
 
Edit: I've calmed down a bit and realised I just need a USB-C adaptor until the fix is made, but I'm still pretty exasperated. Just, bluh.

.... just wanted to let you you know this exact info.

As long as you're going with one (older) display it's not so much of an issue. A USB-C - DVI cable will do.

Trying to connect two of those (older) displays -> you're (currently) screwed
 
@djc6

Can I ask what "had good luck with this cable" means? Kindly elaborate a bit on that.

You know .... it could just be that your display offers the required properties. In that case most cables would have worked.

Works on my HP ZR24w, Dell 1905FP, Dell 2007FP. I got the cable from IT department at work - My 2018 mac mini uses the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter your M1 mac mini does:

 
Works on my HP ZR24w, Dell 1905FP, Dell 2007FP. I got the cable from IT department at work - My 2018 mac mini uses the same MegaChips MCDP2920A4 DisplayPort 1.4 to HDMI 2.0 converter your M1 mac mini does:


thanks for the info!

I briefly checked the displays you mentioned

HP ZR24w -> has HDCP support as per link
Dell 1905FP -> no HDCP as per link
Dell 2007FP -> no HDCP support as per link

I am really confused that the ("passive") cable should make the difference.

The cable you mentioned is HDMI -> DVI-D (single link), the cables I tried were HDMI -> DVI-D (dual link) as per their pictures in the shops and the information provided here

I feel like I am not seeing something here. :-/


...small edit for clarification
 
Updated my Mac mini to 11.1 this morning and am still having issues with HDMI to older Monitor using adapter cable. No idea how long it will take Apple to address this issue.
 
@saulinpa : This is exactly what I see on one of the two HP display, the other one just stays plain black.

I investigated a but further and there is the idea that the HDMI out of the Mac Mini M1 has "HDCP enabled" per default and it cannot be turned off (or it doesn't turn off for non compliant displays).
My displays don't understand HDCP as they are too old, so this might be it.

... that would also explain why the issue happens independently from the cables being used.

I will try one last thing ..... I ordered an HDMI splitter which should "remove the HDCP from the video signal".
For PS4 users this did the trick according to the reviews.

It would be a bit a clumsy solution but temporarily acceptable. I expect Apple will get this fixed as they advertise DVI out via HDMI (and not stating that the display needs to be HDCP compatible). But these might also be false hopes.

The device will arrive Tuesday and I'll report back once tested.

So update as advised: The splitter arrived and to cut a long story short no changes 🤬

I tried it with both display. One stays black and the other shows garbage similar to what @saulinpa described earlier.
Same behaviour as with the HDMI-DVI cables.

I'm done for now.

I tried 50 EUR of cables and splitters and nothing worked.

So what I have is a 2000 EUR Mac Mini M1 that only drives one of my displays where my old Mini 2012 sits there, laughs and drives both of them. Words fail me.

Will send another bug report to apple, sleep it over and then think about purchasing two new displays.
 
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In the end, I just bit the bullet and got a TB3 CalDigit dock. The USB-C MiniDP to DP had problems on display sleep/wake, so I'll just return it when the dock gets here. That also means I can go straight DP to DP.

I wonder if USB-C is less stable than using TB3 dock. I guess I'll find out when the dock gets here.
 
Apple is now telling me that it is with engineering and they have a bunch of complaints. Instead of specific to HDMI->DVI they are lumping it in with other issues calling it "compatibility with external monitors." With that I don't have much faith they will get my problem fixed for a long time.
 
Apple is now telling me that it is with engineering and they have a bunch of complaints. Instead of specific to HDMI->DVI they are lumping it in with other issues calling it "compatibility with external monitors." With that I don't have much faith they will get my problem fixed for a long time.

Thank you for the update on the matter! 👍

I must say that I too have given up on it being resolved soon and ordered a new (2nd) Monitor yesterday.
What should have been an expensive but quick 1:1 migration (Mac Mini 2012 -> Mac Mini 2020 M1) developed to be even more expensive and with "psychological costs" that leave quite a bad taste.

Researching the multiple options given by the wide choice of currently available displays was surely not on the list for the time before Christmas. But I also couldn't bear to have the M1 standing around any longer.

I really keep my fingers crossed that migration assistant will do it's job well and that no more surprises come up.
(..... I have a 10 year old Epson multifunction printer/scanner that is going strong under Catalina .... well I guess I'll see on this one under Big Sur)
 
Just to "close" this topic ... my new Screen (EIZO EV2456) arrived and it (fortunately) works on the HDMI out without flaws. I will now "unwatch" this thread as the original issue will probably be fixed in the next couple of days ;) :rolleyes:
 
I'm late to this topic but can personally vouch for a specific but expensive USB-C to DVI-D adapter that has been working flawlessly for over the month that I've been using it.
My use was to be able to use my older but still great 30" Apple Cinema Display, which is a higher resolution than most and is Dual-Link DVI (DVI-D).

If anyone is still looking and wants to spend the money on this adapter, it does work great for me. But again, it isn't cheap and depending on your needs you might be better off getting a new monitor. Here's the item if you want it:

https://www.amazon.com/gp/product/B07VF1PP8T/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Any takers? Hope this helps.
 
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Just to "close" this topic ... my new Screen (EIZO EV2456) arrived and it (fortunately) works on the HDMI out without flaws. I will now "unwatch" this thread as the original issue will probably be fixed in the next couple of days ;) :rolleyes:
EIZO seems to have problems with newer macs too.
 
Last week, I had a 2,5 hour talk with apple support about my new MacMini where I could not connect my DVI monitor to the HDMI port with adapters.

We figured out that the HDMI port itself works like a charm, when I connected to the TV.

Then Apple support sent my ticket to the engineers, and the reply from there was:
This is a known error. The HDMI port does not support DVI.
This will be fixed in future software update.


So now, I just await any new software updates for Big Sur.

And, for the reference, I already have one monitor connected to the USB-C connection. So this was for a second monitor.
 
EIZO seems to have problems with newer macs too.

Thank you for pointing that out .... now I know I have (and I have seen it) the banding issue 🙄 🤨 😜

Luckily I use the monitor primarily for office work and even when doing some photo retouching etc. I did not notice it.

(snipped)

So now, I just await any new software updates for Big Sur.

And, for the reference, I already have one monitor connected to the USB-C connection. So this was for a second monitor.

That is good .... but with no ETA it's hardly acceptable for most people that right now have one of their existing monitors not working.

I'm late to this topic but can personally vouch for a specific but expensive USB-C to DVI-D adapter that has been working flawlessly for over the month that I've been using it.
My use was to be able to use my older but still great 30" Apple Cinema Display, which is a higher resolution than most and is Dual-Link DVI (DVI-D).

If anyone is still looking and wants to spend the money on this adapter, it does work great for me. But again, it isn't cheap and depending on your needs you might be better off getting a new monitor. Here's the item if you want it:

https://www.amazon.com/gp/product/B07VF1PP8T/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Any takers? Hope this helps.

Thanks! Noted for possible future reference. However, the problem described affects, people that need two monitors working ... one of which must then be connected via HDMI as the USB-C ports on the M1 Mac Mini can only drive one display.
 
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