iMac 27" 5K Late 2015 screen artefacts on shutdown

This has been an ongoing problem with the 2015 build and I have been following these threads for some time. The updated OS Sierra 10.12.4 is reported to stop this problem. I installed it yesterday 2/28/17 and while I feel it is to early to say the problem is solved, perhaps Apple (after years of complaints) has finally gotten the message the problem is real and is attempting to salvage some of its customer base. I have read that a lot of folks are going back to a PC and I confess I bought one as I needed the stability I perceived Apple products offered. Just as an oh by the way, Apple did eventually exchange my original iMac with the one I am currently using only to have the same some of the same issues as the first one. Time will tell if this new update corrects the artifact issues a lot of us are having.

Still no problems! And I've continued to try everything possible to set it off. I hope everyone on here with the issue does the update, so they can confirm as well.

I know some had the issue disappear for a few weeks at a time, but it had been virtually constant for me before this update. It would give me more confidence if Apple had explicitly mentioned the fix in the update, but at this point I half expect they wouldn't want to admit it existed in the first place. Still, so far so good.

I tried for a while yesterday to get the lines to show up (they didn't) but wanted to give the build a few weeks t mature before I started yelling YAHOO! I have to say this however, so far it does appear to have corrected the issues I was having and installing the update was easy enough with no issues. So, I remain cautiously optimistic.

Yeah... optimism grows :-)

I updated my late 2015 imac today to 10.12.4 and everything is working fine.... no artefacts on the first 5 times I've shut the computer down.

it's a good feeling...

Please go on reporting all of you guys who have done the update!

I'm waiting for your feedback. Do you often have color conflicts before upgrading? And after the update - did they really disappear completely? To me it is important - I bought iMac late 2015 m395 and yet I do not update from El Capitan to Sierra. In Russia it was a very expensive purchase. I'm waiting for your feedback - it's important for me to know what can be updated.

I updated from El Cap to macOS Sierra 10.12.4. The problem with the horizontal colored lines on shutdown, seems resolved, but the vertical lines in Time Maschine, they are still. Also the window animation of Mission Control in comparison with El Capitan is very sluggish.

El cap is running smooth and fast on my maschine (iMac Retina 5K 27", late 2015, AMD Radeon R9 M390) so i went back to OS X 10.11.6

Best from Germany

ok... after an intense day on my imac (updated macOS 10.12.4) with graphic work in Photoshop, Office use, Mails, a programm deinstallation, a new installation of the CAD software with USB stick, several user changes and over 20 shutdowns there was absolutely no artefact problem anymore.

And everything is working super sound with the new 10.12.4..... am really happy :-)

Good luck to all other updaters.... please do also report your experiences.

Yes it does. My conclusion is it is fixed. However, my gut tells me to wait a few weeks to before I celebrate a two year fix and a computer replacement. I made the change from PC to Apple because I had heard such good things about it. But having bought what was touted the "Best Apple computer ever made" I found it so unreliable I had to spend more money on a PC to do the work this iMac was going to do. So while I am very hopeful that this corrects the issues many of us have had (at least if fixes mine) the first few weeks of my original iiMac worked fine then started having issues. The same can be said for the iMac Apple reluctantly replaced it with. A couple of weeks of a good working computer then it went to **** so to speak. So the bottom line for me is Apple doesn't seem to care how much of their customer base goes to or returns to a PC. The techs I spoke with really work at a disadvantage as it seems Apple policy calls many of them managers. Heck you can call ne a brain surgeon but that doesn't mean I have the skills or authority to do the job. So...I do hope you have a lot of success with the new build of the OS but for me my iMac is now just an expensive pool table. By the way if your interested, Guarageband doesn't work either try to update the Apple loops and see what happens. I have had several techs remove reinstall only to tell me they will turn the problem over to Apple engineering. Heck it]s their App and it won't load...so you tell me how is your Apple wormy?

I've read some posts in this thread that sounded like people wouldn't buy an iMac because of this "flaw". I guess there are two sides to look at here.

On one hand, the colored lines are something that occur only during shutdown, only last a few seconds, don't damage anything, and don't interfere with anything. It's probably a safe assumption that Apple will find a solution at some point.

On the other hand, it's not too much to expect a piece of equipment of this value to function flawlessly out of the box.

But .... for example, would you not buy a car with an active recall on it for something that will be fixed at some point anyway, if you really wanted that car? Especially if the recall was for something that really didn't affect the way you would rive the car.

kallenemvalts wrote:

Upgraded to 10.12.4 a few days ago. So far no problems. Shutdown behavior is a little different from before: now, it dims the screen background photo for a second, then shuts down cleanly.

Exactly the same for me since updating to 10.12.4. I no longer have the color lines. I do still have the thin vertical lines when I enter Time Machine, but I'm not worried about that.

It would seem that this latest update corrected the problem.🙂 My first two iMacs seemed to have no issues the first couple of weeks and then got progressively worse. I will remain cautiously optimistic for a few weeks for that reason. It would be nice if Apple puts this issue to rest once and for all. I have been watching this forum for some time and so far the general consensus follows the same line as your post. This is good news, or at least I want to see it as good news.

Thanks for posting your outcome.

I've not had it yet since the update (ha ha will now though I've said it!), but I have just had an issue waking from sleep where the screen was black but the computer on - I hit the enter key a few times, nothing, and again when it finally came to life - was almost about to hit the power button. When it came on there was a bit of a graphics glitch too right, not quite bright colours but more the odd horizontal line.

Saying that I do recall sleep/wake issues, quite a bit on Google with these iMacs. But rarely do I have it go to sleep.

I read all your feedback and bought a new iMac 5K late 2015 - FD 2 Tb, M395. Updated to Sierra (clean installation - formatted the hard drive and installed as a clean sheet - not updated), the system boots a little longer, but everything is as before. I shut dow it off several times - I do not observe any artifacts or color lines. Can you have a problem in that you did an update from the old version and not a complete reinstallation of the system?

My first iMac was replaced by Apple. (Thank you Apple). Like the first on after a dew weeks it also began to have the line issue described in this forum. Reformatting the car drive and reinstalling the OS worked for a short time but with in a month the issue seem to come back. I recently installed mass Sierra Version 10.12.4 and had no issues installing it (I started the install and walked away for a while) Since this installation I have had no issues. But I must also say that while I remain cautiously optimistic that the issues have beed resolved for us all, I want to reserve my elation for a few weeks just to see if this actually does resolve the issues. If things continue until the end of March I will be the first in line to say "thank you Apple" despite it taking two years to figure to out. Being glad the iMac Retina 5k late 2015 build owners may have this long over due correction lets see what happens over the course of the next few weeks. I am glad your system functions well and do hope that it continues to do so.

And so, I saw artifacts - a small rectangle 3-7 centimeters below the right of the screen when turned off - held for 5 seconds - did not have time to take a picture. 👿😠The update improved the situation, but did not solve it. The defect does not always appear - 1/10 shutdowns. It used to be just slyly as I understood - now the defect has simply been reduced. I hope this does not mean a problem with the video card.