M1/M2 flickering, ghosting with external display [Merged]

[luckman212]

Wow. Wish I had found this thread before buying my new M1 Mini + Dell S2721QS (connected with HDMI 2.0 cable included with the monitor). I had the flicker/ ghost/ vertical lines problem hit me BAD tonight. Can't get rid of the ghost image even after UNPLUGGING the monitor as well as the Mac Mini... craziest thing I've ever seen. It's like some signal from the M1 is nuking the chip in the monitor. I don't know if this is Dell's fault, or Apple's (my hunch is Apple...) but I am stuck without a working display now

Running 11.5 ... have not tried Monterey but I saw at least one other guy tried that & it didn't help so I am not gonna waste my time.

Anyone know how to factory reset the screen or whatever equivalent of "whacking the side of the TV" is in this situation??

 

[walnut]

Wow. Wish I had found this thread before buying my new M1 Mini + Dell S2721QS (connected with HDMI 2.0 cable included with the monitor). I had the flicker/ ghost/ vertical lines problem hit me BAD tonight. Can't get rid of the ghost image even after UNPLUGGING the monitor as well as the Mac Mini... craziest thing I've ever seen. It's like some signal from the M1 is nuking the chip in the monitor. I don't know if this is Dell's fault, or Apple's (my hunch is Apple...) but I am stuck without a working display now

Running 11.5 ... have not tried Monterey but I saw at least one other guy tried that & it didn't help so I am not gonna waste my time.

Anyone know how to factory reset the screen or whatever equivalent of "whacking the side of the TV" is in this situation??

Just unplug your monitor, and it should go away with some time. The last few posts on this thread seem to be talking about a different issue with ON/OFF flickering and no ghosting (at least they haven't mentioned it). I used to get it at least once a week depending on what I was doing. I can say that I have not had the flickering/ghosting/lines issue since I made the plist fix to get RGB out of the M1 Mac mini. Daily use, for more than a month.

It's been clear that not everyone has had the same success as me, but it doesn't hurt to try. Once I got RGB output out from the Mac, I did not change my display settings at all (4K, 60Hz, "looks like 1080p", default colour display). I assume that if you change your settings, it might re-write the plists and revert back to YPbPr.

 

[satcomer]

so the Satechi hdmi/type c 4k 60hz cable has arrived and as expected everything now works super smooth. No flickering on and off, no other artefacts. 60 hz and any resolution is now not a problem for mba m1. So i guess it comes down to buying a high quality cable. Will update if any issues arise later on

No! The difference is old Cable didn’t support display port 1.4 that handle USB C .2 speeds!

 

[mish929]

No! The difference is old Cable didn’t support display port 1.4 that handle USB C .2 speeds!

the old cable setup was used with the same external monitor and mbp 16" and experienced zero problems, be it resolution, refresh rate or flickering issues.

 

[HumanSquid]

Wow. Wish I had found this thread before buying my new M1 Mini + Dell S2721QS (connected with HDMI 2.0 cable included with the monitor). I had the flicker/ ghost/ vertical lines problem hit me BAD tonight. Can't get rid of the ghost image even after UNPLUGGING the monitor as well as the Mac Mini... craziest thing I've ever seen. It's like some signal from the M1 is nuking the chip in the monitor. I don't know if this is Dell's fault, or Apple's (my hunch is Apple...) but I am stuck without a working display now

Running 11.5 ... have not tried Monterey but I saw at least one other guy tried that & it didn't help so I am not gonna waste my time.

Anyone know how to factory reset the screen or whatever equivalent of "whacking the side of the TV" is in this situation??

You could try under "Others" setting in onscreen menu Factory Reset or "LCD Conditioning" It didn't fix it for me though. When mine did that I closed all windows and just let it flicker for a while it gradually went away. The longer I left a window open that caused it the, worse the flicker got. So weird

 

[fherg]

I updated my M1 Mini to Big Sur 11.5.1 and changed my DiplayPort version on the on-screen menu to 1.1 (DisplayPort to USB-C Cable) LG 32UN500W, happily can report problem's gone... no vertical lines or flickering!

 

[pocketlight]

I'm running 11.5.1 and I still have issues with flickering. I can trigger it instantly by visiting the same specific website now, before it took a minute or so before it started. All I need to do is visit the website I know triggers it. However, it also stops as soon as I leave said website. So I guess there is some steps in the right direction.

 

[mziaeem]

Decreasing the refresh rate to 50 or 30 or using low resolution modes could resolve the problem. I decreased my screen refresh rate to 50 and it's resolved flickering problem for me.

 

[lastkey]

I've U2720Q which I am using with Mac MINI using HDMI cable. I use the same monitor with my office Dell Laptop (USB-C to DP) and my personal Lenovo (TB4 to USB-C). But I use one laptop/mac at a time, so not using multiple inputs simultaneously. I never had any issues with these window machines in the last 8 months.

I got this mac mini last week, and on 2nd day this issue appeared, and as others noted, it only happens on certain websites. It looks like, as luckman212 said, Mac mini is nuking the chip on the Dell monitor. Once the problem starts, it doesn't matter if I use DP (Dell laptop), TB4 (Lenovo); the flickering is visible.

Strangely, after using my Lenovo laptop with the monitor for a while, the issue disappears, and the mac mini was stable for the whole day yesterday, but the issue appeared again today. So typing this message on Lenovo, and as expected, flickering was here, but it is gone now after few minutes of usage.

I am thinking to return this Mac Mini. Advise

 

[lastkey]

I have isolated the issue. It is a particular website (My uni course site on Canvas) and Mac Firefox that triggers this. Ghosting and then flickering. Chrome, Safari has no issues. Firefox on my windows have no issues on that website either. Just Firefox Mac.

This same issue as reported earlier. The Colour profile is YPbPr. Will try to fix to see if it helps

 

[mziaeem]

I have isolated the issue. It is a particular website (My uni course site on Canvas) and Mac Firefox that triggers this. Ghosting and then flickering. Chrome, Safari has no issues. Firefox on my windows have no issues on that website either. Just Firefox Mac.

This same issue as reported earlier. The Colour profile is YPbPr. Will try to fix to see if it helps

I tried this fix and didn't get succeed. The only permanent fix is reducing the refresh rate to 50.

 

[lastkey]

I tried this fix and didn't get succeed. The only permanent fix is reducing the refresh rate to 50.

I’ve changed the profile (plist) and getting RGB from Mac Mini. Now Firefox has no issues. No ghosting or flicker even when I open the problematic page. Before fixing plist. I upgraded to Beta 12 but that didn’t fix RGB. Only plist trick worked.
That mac is too much hassle. I’ll return it today as I’m still in 14 days period.

 

[mziaeem]

I’ve changed the profile (plist) and getting RGB from Mac Mini. Now Firefox has no issues. No ghosting or flicker even when I open the problematic page. Before fixing plist. I upgraded to Beta 12 but that didn’t fix RGB. Only plist trick worked.
That mac is too much hassle. I’ll return it today as I’m still in 14 days period.

Continue to test for a few days and let us know if the issue comes back.

 

[lastkey]

Sorry already returned as I only had 4 days left of free return. Anyway, the Mac also had Bluetooth issues with one of my headphones. I bought the Mac Mini for ease of mind not to indulge in troubleshooting it. My Lenovo Yoga 7 with 11thGen i7 is a breeze to use for the last 8 months. Don't want distractions in my work with Mac creating a mess in it.

 

[Solenoid289]

I sold my M1 Mac mini for around $600 in May because of this.
I was hoping that update will fix the issue eventually but sadly nothing has changed. I should've returned it sooner.

 

[pocketlight]

Running 11.5.2 - Still getting flickering as soon as I visit a specific website. It also lingers a little bit after leaving the website.

Recommending people to lower their resolution or refresh rates are not really an ideal fix either since some of us need to be on native resolution or higher refresh rate to to work tasks.

 

[JDGraph]

Hi all
I just upgraded to MacOs Big Sur 11.5.2 and the ghost issue persists!

I thought it was just my pc until I saw this forum

my mac is

Mac mini (M1 2020)
Apple M1 chip
8GB RAM
My monitor is a GIGABYTE M27F

I have tried with all kinds of cables and ghost problem appears even when turning off the pc

I leave images

 

[rmasoni]

I tried the plist fix but I'm not sure my Dell P2721Q is getting that info through properly. On the monitor's OSD it says YPbPr and when I switch to RGB the colors get crazy.

Issues with flickering, ghosting and vertical lines persist.

 

[walnut]

I tried the plist fix but I'm not sure my Dell P2721Q is getting that info through properly. On the monitor's OSD it says YPbPr and when I switch to RGB the colors get crazy.

Issues with flickering, ghosting and vertical lines persist.

For the plist thing, make sure no other plists exist in either of the locations specified. Remember to give it restart after you're done.

 

[ferjilo]

I updated my M1 Mini to Big Sur 11.5.1 and changed my DiplayPort version on the on-screen menu to 1.1 (DisplayPort to USB-C Cable) LG 32UN500W, happily can report problem's gone... no vertical lines or flickering!

Hi fherg,

still no flickering at all? I have the same screen with flickering on hdmi-usbc or hdmi-hdmi. If yours work well i might get a DP to usbc cable (which one are you using?). Thanks!

 

[pocketlight]

Running 11.5.2 - Still getting flickering as soon as I visit a specific website. It also lingers a little bit after leaving the website.

Recommending people to lower their resolution or refresh rates are not really an ideal fix either since some of us need to be on native resolution or higher refresh rate to to work tasks.

Update from me: The flickering sticks around a lot longer now than before. It does not go away instantly after leaving the website as it did initially.
Uptime on my computer is 9 days, so maybe it has something to do with that. Still using the USB-C cable that came with the screen (Dell P2720DC)

 

[ferjilo]

Update from me: The flickering sticks around a lot longer now than before. It does not go away instantly after leaving the website as it did initially.
Uptime on my computer is 9 days, so maybe it has something to do with that. Still using the USB-C cable that came with the screen (Dell P2720DC)

Did you turn it off/reboot? Is it still that bad?

 

[ryannguyen910]

Had this issue with my M1 Mac mini. My monitor is a new Dell P2721Q, which has a 4K 27in screen. Replicated flickering on dark gradients/colours and the associated image retention. An example that caused this for me was the NoMachine website, which has a black banner at the top and a very dark grey colour right underneath it.

I noticed that this issue was sensitive to the colour profiles I applied to the monitor. I changed to the "sRGB IEC61966-2.1" profile and found that this reduced the frequency (maybe it lightened the screen slightly as well). I also turned the monitor off more frequently when not in use, just in case this was a hardware issue. This only reduced occurrence.

Since there were anecdotes about HDR modes on monitors causing this, and my experience of it being affected by colour profiles, I looked into the colour output by the M1. M1 seems to output in YPbPr mode by default to many monitors using USB-C, DisplayPort, or HDMI. On my monitor, the OSD menu says YPbPr rather than RGB. Turns out, there's people complaining about YPbPr output from the M1 Mac. Luckily, someone figured out a fix (it's in that thread). Ran through the fix, and haven't had issues since (2 weeks and counting). The NoMachine website doesn't cause flicker any more.

Interestingly, DVI connections don't support YPbPr. So if you're connecting with DVI, you may not get this problem. But for many running 4K 60Hz screens, the norm is to connect with USB-C, DisplayPort or HDMI, which do support YPbPr.

My monitor is P2721Q too. I've try fix the problem as you already. Hope it will working!

 

[Chiromac81]

I am getting a M1 Mac air on friday-I was hoping to just use a USB-C cord so I can charge and get the display from the Mac with less cords. Am I to expect problems with most 27-34 inch 4K monitors then using a usb-C cord??

 

[pablo216]

I just turned off HDR Scene and changed to Vivid (or anyone really) on my monitor and this seemed to fix the issue so far. I'm hoping it will stay like this... I'll report in a few days.