iMac 27" 5K Late 2015 screen artefacts on shutdown

I agree with you, I am doubting that I made the right choice with Apple this time, at the start of my problems with my Mac I have taken in back to the store twice they found no issue with it as I said above it finally went to a company called Amsys which found a problem with the logic board they replaced that, and the unexpected reboots have now stoped and now I have this annoying issue with the artefacts lines appearing on the screen. But if I compare my old Mac with this one - my old one performs much better in terms of speed and smooth graphics with scrolling etc. Apple have really cocked up this version of their OS that is, if it is that causing the problem. otherwise they have cocked up the 5K iMacs - sort it out Apple!!!

My iMac will go through stages it will be fine for a couple of weeks then suddenly it will do it on every shutdown - I think it also happens more frequent if I am giving it heavy work like video editing or gaming.

This is a common subject with these computers. After drinking around with mine for about a year or so Apple finally decided to replace my iMac. The new one seemed to work fine for the first few weeks then the multi-colored lines came back on shut down. Apple has done a poor job in addressing this issue and can't seem to find what the problem is. You might take note of place you go to online. I have started to track mine and there are a few that I visit seem to exacerbate this issue. The problem is with the lack luster performance of Apple Corporate taking this matter seriously. Keeping your computer on 24 /7 isn't fixing the issue it is only avoiding it. Come on Apple fix your stuff before a bunch of us go back to a PC.

I am sooooo glad I just found this thread. I have a brand new iMac, 27" 5K Retina Late 2015, just bought it a month ago. I get the colored bars on shutdown, only occasionally. The Apple technician had me do the SMC reset, no change. He said he was going to engineering, but I haven't heard back from him. But it doesn't seem to be a problem as it's not affecting anything. So for now, I will just live with it, with the comfort of knowing that it's not happening in just my computer.

Quick update: two weeks ago I did a clean system install then changed the resolution to 2880 X 1620 (the one just to the right of "Default"). I shut my iMac 27" 5K Late 2015 down every evening (and sometimes reboot repeatedly throughout the day) —I've seen no artifacts on shutdown whatsoever after doing those two things. YMMV.

I think this issue is significant, for what you spend to buy this IMAC don't you think it should function the way it's suppose to. My imac late 2015 27" 5k does the same thing right out of the box after updating the OS. This is my first Imac, 5 days old and don't shut down the right way, might be a sign of things to come😠. I'm returning it back to store and I'll go back to a PC 🙂.

I am on my second iMac as Apple replace my first one. The "artifact" issues while better still happens. I have been following all the messages (and there are a lot) it would appear that a bunch of people with the same iMac have the same issues ad while "Apple engineering" is supposedly looking into the matter the build was 2015 this is 2017 and no fix yet. So... take it from there. Apple has my money once and has no refund policy, tech support try to help early on but then they to get frustrated and stop talking to you or say, "We are working the issue and will get back to you." They don't seem to remember the get back to you part. Good luck..we all could use a bit of that.

All,

Just to add that I purchased a brand new iMac and have the exact same issue. In a way I'm pleased that it isn't a hardware fault and hopefully something that can be fixed with an update.. Heres hoping!

I will try and change my resolution setting as per some of the comments in this thread and report back..

D

Just updated to 10.12.4. I don't want to jinx it, but haven't had the artefacts on the last 3-4 shutdowns. Will be more confident after a few more restarts.

I opened the same set of applications that were almost guaranteed to set it off before, and it's been good. Fingers crossed it doesn't occur again. Anyone else have issues yet with the new release?

I did notice shutdown time have been significantly increased at some times since the update, but nothing over a minute or so in the worst case. I'll take that any day over apocalyptic multicoloured lines of doom.

I have long wanted to buy iMac 5K 2015 (m395), but I was frightened by reports about glitches of the screen when shutting down. I had a iMac 27 late 2012 (GTX675MX), which after 3 years of operation began to issue artifacts first in the browser every 1 month and at Adobe Premiere Pro, Adobe Photoshop and Lightroom. Eventually, he burned a video chip. I really hope for positive feedback that the defect was software and it was fixed. Test actively, it is important for me - I want to buy iMac.

Thank you sooo much helping and so quickly updating to 10.12.4 ! Please, please continue to post your findings with the update. Hopefully 10.12.4 fixes the shutdown artefacts nightmare. I'm crossing my fingers for you/us. Like so many others who have posted on this problem, I am in desperate need of a fix. I'm on my second new iMac with no resolution of the problem.

Here's the background:

I have been an iMac user since the year 2011. However, after this experience, I can't say that I will continue to be.

On Mar 15, 2017, at a physical Apple Store, I purchased a new iMac (iMac Retina 5K late 2015 model, 3.2GHz Intel Core i5 with 6MB L3 cashe, 8 GB of 1867MHz DDR3 SDRAM, AMD Radeon R9 M390 with 2GB of GDDR5 memory, 1TB Fusion Drive, OS X 10.12)

Data migration was done by the Apple Store Geniuses via Migration Assistant from my old 2011 iMac to this new iMac. After about the 5 shutdowns the dreaded screen artefacts appeared. On shutdown the screen would go dark grey followed by about 3 seconds of the artefacts, followed by normal black screen shutdown. I made numerous calls to AppleCare seeking resolution. One person, said Apple is aware of the problem and working on a fix. Another said Apple was unaware of the problem. In all cases the AppleCare people, after going through a few things with me (like NVRam Reset, Safe Mode Start-up) told me they did not know what the problem is due to. Most said they felt it was a software or firmware issue. They suggested a clean reinstall of OS X, something that I was not prepared to do and didn't do. I came away very frustrated and disillusioned with the entire AppleCare experience.

Out of sheer frustration and dispair, I returned the new iMac to the Apple Store. They replaced it with another new one with the same exact spec's. Using Migration Assistant, they did the data transfer from what my new iMac to this new replacement iMac. Then, after their data migration, and while at the Apple Store, I started up the new replacement iMac. Upon the second shutdown, it displayed the same exact shutdown artefacts problem. At that point I went a little crazy. So, the store manager brought out a high level Genius to observe the problem and try to figure out what was going wrong.

First, the Genius ran a diagnostic of the graphics board which showed no problems with the graphic board. At that point, he went into the Genius room to consult with his fellow geniuses. He then told me "their" opinion is that the problem is not hardware related; rather, that it is software related and probably caused by something that migrated from my old 2011 iMac - most likely the USER FILE. And, that while the shutdown problem is a nuisance, it won't damage the computer. In order to identify the software problem he said a clean re installation of OS X would need to be done followed by sequential migration of my files (applications, documents, desktop, etc ... but not the USER FILE). He noted that Migration Assistant could not be used again because it would simply migrate the problem back.

At this point, I have not done the OS X reinstall nor the concomitant sequential files migrations. Seeking a solution to the shutdown artefacts problem has already significantly hampered my work flow. At this point, I can't give it anymore time.

I am considering either living with the problem for now or going back to the Apple Store for a full refund and then going out and buying a PC in its place ... but that opens up a whole new "can of worms" which I'm not sure I want, or have the time, to deal with.

Thanks to everyone who is taking their valuable time to work on this problem. I will continue to vigilantly watch for new posts.

I have not seen the artifacts on Time Machine could that possibly something on your desktop that is bleeding through, also have rebooted twice since the 10.12.4 update and have no colored lines or any other artifacts, I am also cautiously optimistic. I have also changed my display from default to scaled, the box to the left of default, not because of the artifacts but because to works better for my old tired eyes

I just checked my late 2013 MacBook Pro, which has had no graphics issues whatsoever since upgrading to Sierra (also running the latest update), and the time machine lines are there as well. I would say that suggests there is no connection between the shutdown glitch and the time machine lines.

I beg your pardon. I speak German and Russian more than English. The best option is to install the operating system from a flash drive with full formatting of the hard drive. Then transfer your personal files from an external hard drive not through the time machine, but manually. Most likely this way you will avoid the transfer of errors to the new system.

I wouldn't waste my time doing clean installs of the OS. When I bought my iMac a few months ago, I did a clean install of everything and migrated files manually without using Migration Assistant. Still got the artifacts, intermittently. And lately the behavior is changing. One time I saw a ghost image of a text headline that had recently been on the screen. Another time the screen background image "drained" to black from the top down. Another time I saw a small scrambled rectangle inside the screen background image. More recently I'm getting a scramble of colored lines immediately on shutdown, much quicker than before. I still suspect it's a software/firmware problem. Haven't tried the latest OS update yet.