Thunder bolt 3/4 to HDMI suggestion

Hello, I had some problems with a Mac studio M1 MAX and millumin 4.

The device has 3 video projectors. The mac uses a control screen in HDMI and 3 thunderbolt (usb c) to HDMI link. These three links are converted to SDI then to FIBER and finally to SDI again to the video projector.

I specify that the MAC is new and that we have just taken 3 USB C to HDMI adapters of the brand ANKER (

The problem is that randomly the outputs to the video projector switch to black without ever returning to video. It is necessary to unplug and plug the adapter in question.

I have tested the three lines and they are stable. The problem has been solved by replacing the three usb c to hdmi adapters by Belkin adapters.

Also, the ANKER adapters work perfectly on another Mac.

So we have to buy other adapters for this mac studio. Do you have any references that have been tested and proven by the community?


  • Hello @RollTray,

    From what I understand, the problem was the Anker adapter, right ? Why not using Belkin adapters for your other jobs ?

    Also, are you up to date with macOS update ? What is your version ? 13.3 ? If you update to latest version, do you still have the issue ?

    Best. Philippe

  • All the adapters you mentioned are passive.

    You will need to use proper active adapters to avoid the black-screen issue.

    Active adapters cost much more, but are essential for Apple Silicon Macs.

  • edited April 2023

    Thank you for your answers.

    Yes, we bought some Belkin in emergency and they seem to work. I'll see if the Mac is up to date

    Ectoplasosis: like the UltraStudio Monitor 3G? Do you have a reference to recommend?

  • Hello @RollTray,

    I will answer in English, so everybody can understand.

    The Blackmagic Ultrastudio Monitor 3G is not a HDMI adapter at all. Do not be confused.

    What Ectoplasmosis is talking about is the quality of the adpater : passive or activate (better). See this video.

    Best. Philippe

  • Hello, now it's really hard to find the information about active or passive.

    I use a cable from Startech often :

    Câble USB C vers HDMI 4K 60Hz HDR10 2m - Adaptateurs vidéo USB-C | France

    and I don't read this feature active or passive.

    It's written, HDMI 2.0, DP alt mode, Thunderbolt 3 (not 4)...

    With this cable, I never had problems. So far, so good.

    Actually, on an ultrastudio, with 5 outputs I have also problems on the 4 usbc outputs with unknown usbc to hdmi adapters, not switching to black but losing the routing, each time we start.

    The problem is not related to Millumin but to the hardware.

    The Edid is forced by a Lightware grid but it doesn't help. We tried, changing hdmi cables, squeezing the grid...

    On the preference monitor, the 5 displays stay in the right place but not on the physical outputs...

    On a spare Max studio, it's worth.

    Enjoy video !

  • Always use high-quality *active* adapters to avoid issues like this.

  • Hello, thank you for your advice. I won't be fooled again.

    The Belkin's do the trick and I have noted all the references suggested. The Anker we bought was passive but this was not specified in the product description.

  • hello i’m experincing the same problem. Do you think it’s a good idea to use 2 Blackmagic ultrastudio monitor 3g as output?

    My pipeline is:

    Mac studio m1 ultra - adapeter usbc to hdmi - Blackmagic hdmi to sdi converter to an Atem Extreme ISO. so two displays

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