Mac Mini (M1) dual display doesn't work.

I read that particular build had some bug fixes. Maybe around this dual screen issue.

Do you ever have any pink artifacts on the desktop? There’s another thread I’m following with people having that issue. Mine has the issue too. Intermittent and not often at all. But concerning because it’s still there (happened once) since reinstalling the OS

Do you need a developer account on apple to be able to download the beta version of Big Sur 11.1? My version is 11.0.1 and I went on https://developer.apple.com/download/ but there are no beta version showing there.

I have an M1 Mini too. I have an old LG 27" screen with HDMI and DVI. With an HDMI to DVI cable, video doesn't work at all, just completely blank. I have a USB-C to HDMI adapter, and with that the same cable to the same monitor works, except that it will not wake from sleep – I have to unplug the adaptor (not just the monitor) and replug it for it to wake up.

On the same monitor with an HDMI to HDMI cable it works for a few minutes, then starts breaking up and eventually loses picture and sound altogether, though I'm pretty sure this is a monitor issue.

A projector connected directly to HDMI shows a picture, but it's very distorted, showing an overbright interlace-style pattern with a pink and green tint, though you can make out the desktop. Running the same projector & cable through the USB-C adaptor works fine, though I've not tested if it wakes from sleep with that.

I've updated to 11.1 and all issues remain.

Same for me. I made the mistake of changing the orientation of one of my monitors to portrait and then back again. Now whenever it restarts, it restarts in the old orientation (even though it was reset to landscape). The problem is that the other monitor is not the primary (can you change this), so every time I restart I have to try and navigate to the password in the wrong orientation. I am new to Apple and must say that I think this is poor. I know that you guys are notoriously loyal, but your willingness to spend money on adapters to fix an issue that should not be there, amazes me.

I understand your point, but all it does is to show that Apple philosophy is broken. Costumers can't be their guinea pigs. It is understandable in situation like the first iPhone, but not in this case (although the processor is innovative, the bug was in the OS, a product that have existed for decades now). The change in philosophy is damaging the company. As a developer they drive me crazy, changing everything every single year. Things that worked for years stop working or are buggy because they keep changing everything every year, non stop. You can see how that philosophy changed on the consumer side as well by looking at the number of devices they have for sale. It is a mess. Several computers, ipads, iphones, watches, speakers. Even the TV service is confusing (I still don't know if Apple TV is Apple TV+ or what). One of the things Steve Jobs did was to reduce the product line, and all they did since Steve is gone is to add more and more products (all the same, just different models). I hope they change soon, because a lot of people is leaving the platform. Now I have a computer for a few more years, but after this frustrating experience with my new Mac mini I doubt my next computer is going to be Apple.

I have the 16GB/512SSD. Exact same problems as you. Here's my plan:

I've got a "senior tech" person calling me back tomorrow from apple (after two days of trouble shooting and screen sharing). Depending on how that call goes, I'll either:

1. wait for a software update and live with it until then
2. order a new one (and get the 1TB HD) and cross my fingers.

I'll post here and let you guys know what the apple tech tells me.

Please do share what is said. I fear it is a hardware issue. If it were software... the update would have fixed it. I have the return label printed out. Will wait for the word from the apple Tech. I still have my 16GB in the box. Not opening until I see a resolution. I have the 8gb - and the two monitor situation was bad. I have not had the chance to recheck with the 11.1 update.

Pmiles, I'm really not a pioneer, I'm a paying customer. As a developer, I am not completely unsympathetic to teething issues on release. However if I release a product, and there are problems, I immediately: own those problems, explore them, give estimates on when they will be fixed, and fix them. It's great that Apple has created this truly amazing advance in chips. Nevertheless, forgetting to get the basics right: attaching a screen, operation through mouse and keyboard (bluetooth issues), is pretty unacceptable. I am happy to beta test for Apple, but in that case they should take a deposit rather than the full amount and make sure I am aware that the product is not ready.

Thanks for this. You have actually resolved another bug that I encountered. My screen was stuck in 270 degree rotation (I tried it but changed my mind) and would revert back to it whenever I restarted. since this is also the only monitor that would come on at startup, it meant I had to type my password at an angle. Deleting the file in step 3a, has resolved that.

Cheers

Same problem with MacMini M1 2 TB/ 16 GB. Plugged in my two old Samsung Full-HD monitors using HDMI (1) and a USB-C to HDMI cable (2). Black and white flickering. Tried several USB-C Dongles as well as my CallDigit Thunderbolt Dock using different cables. Doesn´t work. Hope Apple takes this serious. I need this machine for work with two screens until my new monitor arrives ...

Apple tech just called me back this morning (12/28/20). She had no more steps for me to try. Said apple engineers are aware of the problem and are researching it. She said she'd call me back with either steps to try or an update to get. She didn't give a time frame.

Sounds like apple's working on it then.

It is running very well with two monitors. I am getting FPS in the mid 30’s with the resident C-172 at KSEA and settings as follows:

# World objects: Max. Reflection: Min. Parked Aircraft: On. Shadows on scenery: Not On. Metal: On. Visual effects: Max. Texture: High. antialiasing: FXAA. Anisotropic: 2X. Using Logitech Saitek Yoke, Power Quadrant, Rudder Pedals.

Apologies for the off-topic post, but the question was asked.

I'll add that switching the HDMI cable on the second display from one input to the other on the display causes it to tell me that a new HDMI connection has been detected. So there is clearly some kind of signal coming over the HDMI connector, but no actual video.

It's a 2018 model I beleive. After I upgraded, the HDMI port on the back isn't working. the thunderbolt to hdmi is working for my main monitor. the HDMI out wont work on the 2 monitors I tried, and with 3 different cables, and confired that the cable and monitors worked by hooking them up to my PC.

Mac Mini dual display problem. Mac Mini M1 16Gb 2TB SSD tried to connect directly with HDMI to my Samsung Odyssee (C49) did't get my maximum resolution. I 've set my Samsung Odysse to PBP (Picture by Picture) so it acts as two displays. Connected two high quality cables: HDMI Mini to HDMI monitor and USB-C Mini to Displayport monitor. I did get two screens, each screens 2560 x1440 resolution. Unfortunately the second virtual display which with the USB-C to Displayport keeps flickering the message Check the cable connection and settings on the source device DisplayPort 1.

I've invested in the Mac Mini because of the performance of th M1 processor and because it would support 5K displays. Unfortunately the display support and resolution is very disappointing!

Hopefully Apple will resolve this issue very soon.