2020 iMac Screen Glitch on Shutdown

on my computer, the same glitch was appearing during turning-off or restart. My scare was just that a brand new computer was going to have your same problem in a couple of months so, I preferred to let the customer assistance doing their job and fix properly my brand new computer

They wouldn't give me any details other than it was most definitely not a hardware fault - well I kind of thought that considering how many of us have the issue and it did seem extrodinary to think there were so many pieces of flawed hardware out there and as you say, like me, this isn't replicated under the previous OS Catalina. It doesn't affect performance or anything as far as I know but for Apple this sort of thing should not happen so I won't be Big Surring again anytime soon until this is sorted.

I know it's not for this thread but I found other annoying issues with BigSur that aren't getting addressed, severe Bluetooth non-responsiveness / lagging for one, but that's not for here!

Hi again... I also believe that it will be ironed out sooner or later. But I am just curious. ..If some software bugs causes this glitch like apple tech guy says so, why it doesn't happen to all who are using same software, big sur? Or apple wants us to believe it is not a hardware issue.

This very much amplifies my point - this has to be software related. No way can we all have dodgy graphics cards?

Not a hardware issue in my opinion. It is Big Sur. How do we get Apple to address this?

I have the EXACT same issue. My 2020 iMac has the 3.8GHz 8-Core i7 with 5500XT 8GB graphics. I've tried resetting the NVRAM/SMC and reinstalling the OS, as well. This issue occurs with Catalina 10.15.7 and also with Big Sur 11.1.

P3-Mac, are you noticing the issue on your new (replacement) iMac?

Spinnetti, have you been able to resolve your issue?

Thanks for your help!

He Mike,

I see what you mean and indeed what your saying is what i experienced before... shutting down within a few minutes didn't show the problem. Using it for longer period of time, it did show the problem.

I haven't yet tried using the Mac for longer period of time yet (let's say 30 minutes plus) and yes i am a bit afraid it may show the issue once again then so i will test it out this coming week. But after the update i noticed it was not happening so i immediately was curious to see if anyone else had the same experience but as i am reading through the responses i am afraid it has not yet been resolved.

Will post if i have more feedback on the issue. P.s. i am finding it very strange that Apple haven't responded anywhere properly to this issue. It's so obvious that something is off here and let me assure you that a lot more people then just us will have this same issue. A lot of users will probarbly ignore it because it's not something which interfears with our work.... the mac is working and who is actually watching the shutdown process??

Really odd. Mac should be the topnotch computer brand so why don't they act on this. You cannot tell me they don't know about this problem, no way, they do. So perhaps we should bring the issue into a bigger audience?

P3-Mac

I just purchased a 27” iMac 5K retina with the highest video card and I happened to have the same issue you are describing right out of the box. I actually have the same screen background.

Where you ever able to solve the problem. I’m considering returning my computer as I’ve only had it for less than a week. Any information you can provide I would greatly appreciate it.

FZ

StudioViv,

Thank you for the reply. I do appreciate you going through the details of what you have done in order to try and fix this problem. I was really hoping there was a fix to this especially since the computers are not cheap. I too hope it's just a software problem and not a hardware problem. I don't know if I could handle the same problem occurring when a new OS is released, or worse getting white strips across my screen like others on other forums have detailed. Apple should have addressed this already like you mentioned to give users an explanation and their plan moving forward.

Even though I already sold my previous iMac, I think I am going to return the computer and wait until this fall before school starts back up.

Thanks again,

FZ

Hey P3-Mac,

I hope this issue is software related. It's some trouble to pack everything and return this elegant beast and do a migration again.

It stuck me that this issue is so well described and still there is no answer from Apple. I can't fix this myself. Also the latest 11.3 MacOS didn't resolve this issue. I gonna call them this week and also direct them this forum. Maybe it will get some attention.

Hello Guys, I have a brand new iMac 27 2020 i9, Big Sur. As you can see from the picture I got the same problem during the shut down or restart. It appears randomly, as many of you, if I use the computer more than 15 mins. Did someone understood if this is a OS problem or an hardware problem? Even if this problem is not affecting my work, is annoying coz I am worried that can be a hardware issue and in a future I don’t want to spend money for it. Thank you in advance for any reply

Agreed, it COULD be a hardware issue but the fact there is different hardware involved across the Mac's (iMac, MacBooks etc.) that this is happening on, I still think this has to be software related. I still think it would be nice to get some clarity from Apple as their approach to this doesn't seem to be anything like as direct as it should be.

I also noticed my keyboard slip in my last message which might just a bit on the nose when I referred to Big Sur as "Bug Sur" ;-)

I did do an OS report about this issue but of course these reports don't generate a response.

Hello Guys,

at the end, considering that I bought the computer just a month ago, I opted for sending it to customer care hoping that they will fix the glitch. I think that by a week I will have news about it. I’ll let you know how they’ll fix the problem so might you fix it as well.