Level 1

22 points

iMac 27 inch 2020 - Screen Glitch (Random Lines Appear on Screen)

I've just received my new iMac and noticed that from time to time a line glitch appears on my screen.

It's completely random, I thought it was related to intensive work/heat but sometimes even when the computer is idle I see the line on the screen.

It was really hard to capture it because it's so random, but I manage to record the moment a glitch happens. Unfortunately there's a lot of white background on it which makes it hard to see, but it goes across the entire screen https://www.youtube.com/watch?v=xw8Z4mVgYgE

The iMac is running fine, I ran all sorts of benchmarks for CPU/GPU and it's all OK, but from time to time I see this annoying line on my screen.

iMac Line (2012 and Later)

Posted on Aug 26, 2020 7:21 AM

Top-ranking reply

Old Toad

Level 10

215,250 points

Posted on Nov 8, 2020 2:27 PM

Try the following: download and apply the macOS Catalina 10.15.7 Combo Update

It fixes this issue:

• Addresses a graphic issue that may occur on iMac (Retina 5K, 27-inch, 2020) with Radeon Pro 5700 XT

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249 replies

Xfinite

Level 1

4 points

Aug 30, 2020 9:25 PM in response to Bunn_pt

I have the same issue, but not very frequently happen on MacOS. Also, this issue seems not exist on Windows10, Maybe it's the GPU driver issue.

Sep 4, 2020 5:41 PM in response to aaronshort

So you hear the fan when doing non-intensive tasks? What iMac configuration did you buy?

gurman42

Level 1

17 points

Sep 8, 2020 7:20 AM in response to jginnever

https://www.apple.com/feedback/imac.html

[Edited by Moderator]

Sep 10, 2020 1:44 PM in response to Cesium06

It only happens at the default resolution, in Mac OS (not in Bootcamp) and without a second screen attached so I would say it seems to be software related.

stephanM

Level 1

4 points

Sep 22, 2020 7:12 AM in response to Bunn_pt

Well I just returned mine before the deadline, I saved a couple videos showing the glitch in the setup screen and the square corner on the FT window, anyone know the best way to send it to apple?

Sifacosi

Level 1

4 points

Nov 12, 2020 1:43 PM in response to gurman42

I switched to dark mode too. The sharp corner glitch was still there. I returned it and Apple told me they don’t know when they will address this issue!

aforchie

Level 1

8 points

Nov 23, 2020 10:57 PM in response to Bunn_pt

Omg. This issue was solved with a minor software update like 2 months ago. It’s over. How the heck do i unsubscribe from this thread? NON ISSUE.

phlexib

Level 1

4 points

Aug 30, 2020 11:13 AM in response to Bunn_pt

Same for me.

it started as soon as the first boot.

it’s not that frequent but does happen , even with no app opened.

i also get random crackles and distorsion on the built-in speakers, as well as loss of sync playing video. Only with the built-in speakers. But that’s for another thread.

Aug 31, 2020 3:48 AM in response to Greenycq20

Have you received your replacement unit yet and has your issue been solved? I too get the line from time to time, but what is worse for me is the complete system crash looking like your screenshot, after playing Civilization VI through Steam for 10-15 minutes. I wonder if the issues are related.

Bunn_pt Author

Level 1

22 points

Aug 31, 2020 4:47 AM in response to Glennovich

I didn't ask for a replacement unit, I'm not sure if it's hardware of software yet and I don't want to go thru all that hassle and wait ~2 weeks without a mac to end up having the same problem again. I tried to call Apple 3x already but every time the call drops, super annoying.

radu_d

Level 1

4 points

Aug 31, 2020 4:54 AM in response to MartinBier

Hi guys, I noticed the same lines glitch last night while watching Apple TV. I've had my 2019 Imac , 3.7 Ghz i5 , 8GB RAM , Radeon Pro 580X 8GB for two months now and this is the first time I've experienced this.

I updated macOS Catalina 10.15.6 about a week ago.

Today while watching YouTube the glitch started again.

Need some advice please on what to do next.

Thanks

Aug 31, 2020 4:52 AM in response to Bunn_pt

Does anyone NOT have this issue? I was about to buy that configuration with that video card but am holding off to see if it’s hardware or software. Sad to hear this. Was so looking forward to finally owning a Mac.

Aug 31, 2020 6:28 AM in response to Bunn_pt

Oh good I'm not alone - I'm having the exact same issue on my 2020 iMac with the Radeon Pro 5700 XT 16 GB. Hopefully it's just a driver issue. For me it's really not all that frequent or annoying but I do notice it when it happens.

mristi

Level 1

4 points

Aug 31, 2020 8:24 AM in response to airpoint

uff this is unsatisfying - not quite the answer all those experiencing the issue are looking for. Apple should really look into the matter, open files of users describing the problem and do trouble shooting on their end. Considering the vast amount of people complaining this "glitch" will not go away after getting a replacement anytime soon.

Hopefully blogs like 9to5mac keep on posting news about this, so some people at Apple finally acknowledge the issue.

Bunn_pt Author

Level 1

22 points

Aug 31, 2020 9:11 AM in response to airpoint

@airpoint yeah, that's what I thought it was going to happen, I don't want to have to go through all the hassle of shipping the iMac, probably waiting ~2 weeks for a replacement just to have the same problem again. Ideally they would recognize the issue and say that it's either going to be fixed in a software update or a hardware recall. I'm basically waiting to see if they will do something about it. I'll give a couple months, if nothing happens I'll try to replace it =/

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iMac 27 inch 2020 - Screen Glitch (Random Lines Appear on Screen)