Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Do you use variable refresh rate with your external screen?
I've tried that option (only available on the Thunderbolt screen), but it didn't make any odds. Bizarrely changing the colour profile for the display seems to have calmed it down dramatically - it still does it, but it's a lot less noticeable now.
 
When I bought the new M1 Mac mini I assumed I would be able to drive two displays from the Thunderbolt ports (because the previous gen. intel Mac mini it was replacing could drive two displays from any two of its four Thunderbolt ports). Seems like the M1 Mac mini is a significant downgrade compared to my previous i7x6 Mac mini – no wonder my Intel Mac mini sold for more that the asking price of the new M1 machine!
 
Hi folks! I've got some solutions here- WHOO! This problem drove me crazy, but I figured out a fix (other than the earlier suggestions!) For reference, this was with a BenQ PD2700U monitor.

1. There appears to be a bug in some versions of MacOS (including the most current one) where ICC V4 profiles or above cause external displays to flip out and do the pinstriping/flickering/etc. Using an ICC V2 profile should help in your display settings. (You can also verify ICC versions by using the ColorSync utility).

This seems to have worked! I checked the ICC version for the BenQ profile and it was v2, not v4, but I still got a ton of flicker on dark backgrounds. I've switched to "Generic RGB Profile" which is also v2, and the flickering has gone! Fingers crossed it stays that way!
 
I accidentally found the cause of the problem. Lighting a lamp in my office, after a minute, the problem started to appear. I linked this to the True Tone feature. I then tried to turn it off and slowly the monitor stops flickering and ghosting, turning the True Tone back on the problem comes back. After some days I can say that monitor flickering is gone... hope
 
It was disabling the True Tone in display settings that solved the issue for me.
 
Thanks anzyliao, this solution actually fixed my problem with external monitor.
Had it every day in evening for half a year, tried everything I found about truetone and colour profile.

Curious how many time it will take Apple to implement this fix, its seems to be around for couple of years now.
 
Like others have noted, this seems to happen when the screen is dark and there are bright elements somewhere on the screen. I get the pinstrip effects others have noted.

I don't think this is caused by TrueTone - I think disabling TrueTone makes the screen brighter, and a brighter screen doesn't have the same effect. But if you find the right type of image, the issue will still happen. Same thing with Night Shift - it seems to make the problem go away because the screen gets brighter.

I have tried the video from GetVladimir, the script from Anzyliao, and several other options in this forum. None have actually resolved the problem.

I am able to reliably reproduce the problem by finding a dark movie trailer. Inevitably, one of the frames will flicker. I can even pause on that frame, and the flickering will continue when the movie is paused - a 100% reproducible event.

The Dark Knight Movie Trailer, fullscreened, has this issue between 0:45 and 0:55 on every combination of settings that I've tried:

Can others reproduce this as reliably as I can?
 
I've tried everything and this problem made me crazy. I finally fixed it by forcing mac output from YCbCr to RGB

I used the script https://pastebin.com/GvqHiiMe. You can find many other videos or posts on how to do it
Update:

I found the mac output would be back to YCbCR when unplugged and re-plugged the cable from the mac. Even after rerunning the script at this time, the output was still YCbCR. The script can't fix the problem permanently.

I believe the YCbCR is still the root reason for flickering. I tried the different cables, like usb-c to HDMI, usb-c to usb-c, HDMI to HDMI, and usb-c to DP.

Finally, I found that the usb-c to DP cable consistently outputs RGB instead of YCbCR automatically, which fixed the flickering problem.

I have two monitors, a dell u2720qm and a u3223qe. I've tested on both monitors and got the same result.

If you have a flickering problem, try a usb-c to DP cable and check if the input color format is RGB on the monitor menu. Most likely, it will resolve the issue.
 
Update:

I found the mac output would be back to YCbCR when unplugged and re-plugged the cable from the mac. Even after rerunning the script at this time, the output was still YCbCR. The script can't fix the problem permanently.

I believe the YCbCR is still the root reason for flickering. I tried the different cables, like usb-c to HDMI, usb-c to usb-c, HDMI to HDMI, and usb-c to DP.

Finally, I found that the usb-c to DP cable consistently outputs RGB instead of YCbCR automatically, which fixed the flickering problem.

I have two monitors, a dell u2720qm and a u3223qe. I've tested on both monitors and got the same result.

If you have a flickering problem, try a usb-c to DP cable and check if the input color format is RGB on the monitor menu. Most likely, it will resolve the issue.
Never mind. I gave up. I feel like it can't be fixed
 
I purchased DP to USB-C at your suggestion, and it has not resolved the issue. Nothing has changed.

I have a Philips monitor. Philips support is sending me to this thread and telling me to ask Apple, and Apple is telling me it's a monitor issue.
 
Hi All.

I recently got an Acer VG272U to use as an external monitor for my 2020 13" M1 MacBook Pro. I'm also having extreme flickering issues on this external display. The display is connected via an Anker 7-in-2 adapter, using a HDMI cable.

The issue seems to be directly brought on by watching any form of video (YouTube is a prime cause), or using the MacBook's built-in camera when connected to the display. The issue seems to not happen randomly for me anymore (I hope), and is only brought on by these two scenarios - I can browse safari, do my work, play chess etc all fine so long as I do not watch any form of video.

I have been back and forth between Apple and Acer now since I obtained the monitor, and nothing either party has said or suggested as a fix has actually come even close to resolving the issue.

The monitor sees the flickering issue when also connected to my iPad Pro, but I tested a Chromebook and the issue is not present when that is connected. It seems to be an issue concerning only Apple devices.

Acer have flat-out told me that there must be a compatibility issue, and to return the monitor, take my MacBook to a store where they sell displays, and plug it in and test every single one until I find one that doesn't have the issue!

I find it absolutely appalling that such a huge company can allow such an issue to go on for so long with no fix. I was even looking into the possibility of downgrading my MacBook to an intel model, as I hear the issue is not present on these MacBooks.

Honestly I wish we could all band together and force Apple to do something via legal action. It should not be allowed that they produce devices incapable of such a simple task. It should be law that they ensure they are compatible with at least a portion of 3rd party displays, or at least can provide a list of ones which are 100% compatible - because when asked no technicians could even give me that! But you can bet 100% that their own $1500+ displays won't see this issue! It reminds me of the battery life scandal all over again!
 
There was a similar problem with the monitor Xiaomi MI 27" (FHD).
The picture flickered on a dark background. I've tried all the tips in this thread. For connection, I used HDMI-HDMI connectors, Type-с-HDMI - nothing helped.
The problem was solved only by replacing the monitor with MSI MD 272qp (2K)

P.S. A bunch of a Lenovo laptop (Windows) and a monitor Xiaomi had no problems with flickering.
 
There was a similar problem with the monitor Xiaomi MI 27" (FHD).
The picture flickered on a dark background. I've tried all the tips in this thread. For connection, I used HDMI-HDMI connectors, Type-с-HDMI - nothing helped.
The problem was solved only by replacing the monitor with MSI MD 272qp (2K)

P.S. A bunch of a Lenovo laptop (Windows) and a monitor Xiaomi had no problems with flickering.
Hi Raa78,

That's interesting. Now that you are using this new monitor are you experiencing no problems whatsoever?

I have just discovered that the HDMI port on the Anker adapter I am using only supports 4k @30hz, while the USB-C port supports 5k @60hz. I am going to test this with a USB-C to HDMI adapter, and report back as to whether this has fixed the problem.
 
Right, I think I have solved the problem.

My MacBook runs at 60hz. My adapter was an Anker 7-in-2 device which only allowed 30hz output via the HDMI port. I have tested a separate USB-C to HDMI dongle and the problem seems to be entirely resolved.

I played videos in full screen, used the camera on my MacBook, and still no issues!

I have now purchased an Anker 8-in-1 adapter, which only takes up 1 USB-C port, and also allows 4k @60hz via the HDMI port.

I am a skeptic so I must say this: even if this for some reason doesn't work using the HDMI directly into this new dongle, I will still have a spare USB-C port on the MacBook itself, so I can use the USB-C to HDMI dongle I am currently using, which I know does not experience the problem.

Let me share my entire setup details in the hopes that this is of any use to you guys.

- 2020 M1 MacBook Pro 13"
- Acer VG272UV monitor
- Standard HDMI cable which came with the monitor
- Cheap USB-C to HDMI dongle from Amazon (make sure this supports your resolution and 60hz) -> I will be swapping this out for the new multiport one I ordered from Amazon, via Anker, when it arrives tomorrow.

Additional info:

I have gone through all the troubleshooting steps with Apple support, deleting various files from the library, trying safe mode etc. While I believe that the problem for me was entirely caused by the incompatible HDMI port on my adapter, I believe for transparency's sake I must mention this additional info.

I sincerely hope this is helpful to anyone, this problem has been infuriating, but I am relieved that in my situation it seems to be a relatively simple fix.

If for any reason the issue persists (I'm begging it doesn't ahaha), I will come back to update this thread.
 
Hi Raa78,

That's interesting. Now that you are using this new monitor are you experiencing no problems whatsoever?

I have just discovered that the HDMI port on the Anker adapter I am using only supports 4k @30hz, while the USB-C port supports 5k @60hz. I am going to test this with a USB-C to HDMI adapter, and report back as to whether this has fixed the problem.
Hi Klarhmt,

After changing the monitor, the flickering problem was no longer observed. I checked the connection via HDMI, Type-C and Docking Station.

For the experiment, I connected MB Air 2020 (Intel i5) and MB Air M1 to the old monitor - on Air M1, the problem with the flickering of the external monitor also appears.
 
UPDATE:

The problem is still occurring.

It's seemingly only triggered by watching video on the external monitor now. Netflix always triggers the issue, I have seen less severe cases of it when watching on other sites, but it still persists.

I am going to try again with calling Apple as this is clearly a problem with their devices. Given they haven't even been able to provide a list of monitors that the M1 models 100% work for, I am utterly shocked how this isn't being reported in the news as a scandal. How can they claim to be compatible with external monitors, yet clearly this claim is entirely false. These fraudulent claims are disgusting.
 
Evening all.
I'm having exactly the same issue as detailed above, with my week-old M2 mini & one year-old Dell S3221QS.
I've tried everything mentioned previously and it's still the same - flickering/pinstriping on dark grey & black content - especially with video.
Lots of folks with Macbooks mentioned turning off 'True Tone', but I don't appear to have that option with a mini.
I'm now looking at a replacement monitor, but I have no way of knowing which monitors are immune from the problem.
 
I dunno... but since Mac os 13.2, i haven't had a single flicker so far .... using via TB port on my 27 Inch 4k BenQ.
 
Issue still persists with brand new Macbook Pro M2 running MacOS 13.2. I'm using Anker 8-1 adaptor to connect HDMI Dell p2317H monitor. I've tried basically every suggestion here as well as those here:


I Was hopeful that the upgrade to Ventura 13.2 would fix the issue, but it did not.

I called apple and the representative said that the Anker 8-1 adaptor could be the problem and Apple only recommends we use Apple products. As far as I'm aware there isn't even an apple USB-C/thunderbird 3 to HDMI adaptor so the recommendation was not very helpful.

Seems like the issue has been around for years and never addressed by apple? and no real solution?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.