Mac Mini M1 Screen Flicker

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Level 1

24 points

Mac Mini M1 Screen Flicker

Hey

I have a newly acquired Mac Mini M1, to replace a 2015 MacBook Pro. I used the MacBook primarily as a desktop previously and so the Mini is a good solution as I don't really need portability.

I have the Mini connected to 2 external monitors, both are AOC U2878G6 28" 4K minitors. I have one into the HDMI port and the other into Thunderbolt via a high quality HDMI to Thunderbolt converter.

I'm suffering from screen flicker on the screen that is directly connected to HDMI only. It comes and goes without obvious reason as to why - i've checked the Activity Monitor for example and it's not when the CPU is loaded or anything simple like that. I've also changed the HDMI lead just on case but to no avail.

I see there is other traffic on screen issues although most is about complete flciker such that the screen can't be read where in my case, it's flicker as if the hertz band is out for a moment, like you would get on a TV that's overloaded by a green screen background and can't handle the contrast well.

Using my computer in dark mode, as i have always done since that was launched. I don't know whether it's blacks and dark colours that may be the problem?

Any advice from the community would be welcome.

Mac mini, macOS 11.2

Posted on Feb 5, 2021 6:35 AM

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Answer 1

Top-ranking reply

Integrity Kevin

Level 1

9 points

Feb 26, 2021 3:14 PM in response to mikkibarry

Similar problems here, using Dell 4k monitor, have changed from using HDMI to using Thunderbolt port changing both cables and ports still have awful flickering regularly. I almost thought I had it reproducible this afternoon but alas it evaded me. I've been turning off all the maccy animations since at times it seemed to follow mousing over areas where macos was desperately trying to look cool being extra translucent.

At this moment, display looks normal, I have Messages up and using it but everytime I mouse over the i for info in top right corner of the window, the screen starts flickering. Looks like a bad cable would if you didn't quite have it plugged in. Move mouse off it and normal, hover flickering, move normal. I will say I'll come back in 15 minutes and this hover will not cause it to happen. Very bizarre. As the weekend arrives I will have much more time to tinker with it and try to figure out what is happening, including swapping the monitor but I really don't think it is the monitor which has worked flawlessly with several Windowz and Linux machines for a year or two.

Love this thing's speed, almost seems comical sometimes how fast, but the hassles are mounting and I regret not letting others work out these kinks before I bit. This looks its best if you just turn on the screen saver and watch it. Using it is painful. Fast but painful.

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Answer 2

Androish

Level 8

39,487 points

Feb 5, 2021 6:47 AM in response to athol161

Have you tried to switch which of the screens are connected via HDMI?

Just to rule out the specific screen.

Other than that if the issue happens only when you are connected via HDMI on the Mac Mini, that might point to either a capability issue or a hardware issue with the mac mini.

The screens work fine with HDMI connected to other sources(like the old MacBook)?

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Answer 3

athol161 Author

Level 1

24 points

Feb 6, 2021 3:41 AM in response to hcsitas

It's not the cables, they are short and I have been using the same ones with my macbook and the same screens for 3 or 4 years without any issues.

I switched every setting to Light Mode and the flicker has stopped so it looks to be something that only occurs in Dark Mode. I assume the graphics and/or processor can't handle the black and dark colours. I'm hoping it's soemthing that a furture software update may address.

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Answer 4

athol161 Author

Level 1

24 points

Feb 5, 2021 9:24 AM in response to Androish

Thanks for your reply.

I've ruled out a specific screen and have tried switching the HDMI around etc. I used these screens with the old MacBook for 2 or 3 years with no issue.

An update however, I have changed all my settings to light mode, including the similar setting on Firefox (which is the browser I use), and so far the screen is not flickering.

So, perhaps this is a software issue on dark mode only which is something that could be fixed with a Big Sur update whenever that comes.

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Answer 5

Feb 11, 2021 7:27 PM in response to athol161

Similar issue here. Dell 4k display. All of a sudden, it started flickering. Nothing I seem to do is helping. Changed resolution. Changed input from HDMI to USB-C and back, rebooted the machine, restarted the monitor, nothing!

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