iMac 27" 5K Late 2015 screen artefacts on shutdown

Hi,

I have problems similar to the iMac 27 "Retina 5K late 2014 model. After quenching becomes transverse color lines as many users here. Is MacOS Sierra problem or a hardware problem. Will El Capitan same problems?

I also installed a new developer version of MacOS Sierrasta, but two days have been used. Yet I can not say whether the problem.

These photos were taken before the beta version. This is a public version of MacOS Sierra

I just bought a new 27" iMac in Dec 2016. Have the same problem.

My iMac isn't even a month old.

Does anyone know if Apple addressing this issue on iMacs they are currently selling?

Anything we can do if trying to make "new" purchase?

Aklion,

I did what you suggested. I reported to the feedback team today, Jan 13, 2017.

I bought a 27" iMac just a few weeks ago, and have seen green, pink, and black horizontal

lines across the entire screen.

What baffles me is why they keep shipping it with a known problem.

Hey, the same problems persist even if the latest MacOS Sierra developer version is installed. My iMac (Retina 5K, 27-inch, Late 2014), which is a customized version. Maybe I should go back to El Capitan and experiment works better?

Here is a picture after shutting down. May work better after the new update, since there is no time to become

I have the same problem bought me iMac 27 "5 k i7 ssd m395 2 Gb.

Several have changed me what times is the third iMac that I sent and the same attached a video.

https://youtu.be/-zZWuYto9gQ

And a screenshot of the video image.

I don't know if return it and wait for the new 2017 or wait for Apple to fix it.

The iMac works correctly.

Thank you.

I have just received a new iMac 27" 5K Retina from Apple in replacement for a so called faulty model which also exhibits the same shutdown artefacts as the previous one did! Apple went to extraordinary lengths to try and fix the previous iMac. They replaced the LED screen twice! The main mother board twice! as well as both RAM chips and to no avail. That's when they decided to changeover the entire computer at no charge to me. The handling of this was impeccable and while I still have a (new) computer with exactly the same problem, I am pleased to know from this forum that apart from this quirky shutdown artefacts syndrome, the computer works beautifully! I sincerely hope that this quirky problem is fixed in the forthcoming Sierra update to 10.12.4 Apple should be aware of the problem by now and I would be going to Apple Support for help in fixing this problem as it seems that it affects all 27" iMacs with 5K Retina under Mac OS 10.12+ Hopeful that a firmware/software fix will happen very soon!

Update: I don't know where I saw this (maybe some pages up on this forum), but this has fixed the problem so far (last 2 shutdowns at least - fingers crossed):

Change the resolution from 'default for display' to one to the right. 2880 x 1620.

Haven't tried any other settings, but problem seems to have gone away on past 2 shutdowns. Will verify. Anyone else want to try this?

Another day without artefacts! I am cautiously optimistic.

In response to some of the other recent notes here, I didn't notice before but I do see the vertical lines in time machine. I probably never noticed before because I rarely go into the restore. (Screenshotted). Still, this is the longest I've been without the screen artefacts, and I've been careful to reproduce the situations that always set them off before. (Running graphic-intensive programs like MineCraft, and shutting down before closing all programs or unmounting drives in my experience).

As to the clean install/file migration, I've tried it both ways. On my first iMac, which I returned initially due to this issue, I used the migration assistant from and external drive. The issue appeared the minute I installed Sierra, and not before. Then, with this current iMac which is the same in every respect, I did a completely clean install of Sierra from a USB stick and no file migration initially. Before I moved any of my files or programs over (completely clean system) I tried a shutdown, and the problem appeared instantly on the clean system.

Hi, All,

I was one of the early ones with the multiple problems including shutdown and startup screen issues, having changed the ram and apple changing the motherboard and HD on my late 2015 i5, I finally got feuds with Apple as they swerved changing the machine (in AppleCare warranty!).

I bought an ex-demo i7 4ghz, 32gb ram, flash drive and still had the same sort (slightly less) issues, which included the odd shut-down graphics issues, normally after a busy day.

To be honest, like most I decided to live with the problems, I'm talking about multiple little problems as well, and I don't have lots of nonsense downloads or dodgy apps either, this is a work machine that's looked after.

The annoying thing is for 25 years and maybe 20 Macs, I couldn't name you any problems at all, ever... and since December 2015 the two late 2015's have been a constant nightmare, the problems rotate, I may have them for a month or two, and then they come around again.

I am now having a problem with icons doubling up in finder and also finder restarting when I select the applications folder; I haven't had this for maybe three months.

I also have a weird issue that's new, the top right hand of my screen, the grey bar which has the date is pink, it fades back to grey after maybe 5 inches if I screen grab it the picture is grey, but I have taken a picture with my phone - included.

Also have a problem with the fan; sometimes it works, sometimes it doesn't.

I have upgraded to High Sierra in the hope it would cure the fan, so far it has, BUT

Huge screen artefact just a minute ago, a big multicoloured flash and what sounded like an electric spike or short.

The fun never stops, do I want to start now leaving this one with AppleCare for two weeks to be advised everything is fine...

Not really...

Agreed, on the late 2015 iMacs, I still think its graphics related, although, I had everything replaced on my other late 2015 i5.

I have just looked up the cost for a new iMac with the same spec as my i7 - £3,638.

Although they are offering £495 for my Late 2015 27" i7 4Ghz, 32GB ram, 512ssd - I'm was tempted and then saw they have a refurb i7 - same date and spec but with 16GB on sale for £2,700!

I would probably get around £1700 for mine on the market, but wouldn't feel right passing it on as it is, I'm now living with the problems, as I have since late 2015.

I have ongoing glitches (most days), a restart normally sorts it out.

What's puzzling to me is the list of problems I'm having, it's always changing, I find as one glitch fixes itself, something new will happen.

The startup and shutdown artefact glitch fixed itself for a few months, then appeared back with HS.

It hasn't happened for quite a few days now.

But, I am having this today, and it's a brand new glitch, for me anyway.

Glad to hear you got everything sorted and your 2017 iMac is good, you never know, I might get tempted, but can't see it yet.

Obviously it should be red (as bottom) but after a short sleep the colours shifted, only a file save and PS restart would fix it.

Just as a final note, I have noticed the screen colours a lot darker, just thought I would mention.

The thread has been quiet so hopefully its just me!

Is this definitely a software issue? I've been reading online.

Isn't this a video card issue?

They seemed to have had one back in 2011 and 2012

iMac (27-inch): AMD Radeon 6970M Video Card Replacement Program - Apple Support

I just found this thread today, Jan 13th. So, I'm not sure if it's software or hardware.

I, too, have heard from Apple since posting here.

Apple is very interested in solving this problem.

1) I think it helps to post screen shots of what is happening. Apple can see what's happening on our screens. I did post an image of mine.

2) Posting images will help the Apple systems engineers see similarities and differences.

I could see that the images others were posting were very similar to mine.

3) I also used the link that Etuj posted in this thread on Dec 8, 2016 to report issues to Apple.

http://www.apple.com/feedback/macosx.html

We need to keep posting so Apple has more information.

In the meantime, I'm expecting another 27" iMac, Retina, 3.2 GHz, 1 TB flash drive to be delivered today or tomorrow.

It's helpful to know others are having the same issues.

If it's a software/firmware problem, will Apple notify us that it's been fixed? The Sierra 10.12.3 release notes don't mention it: About the macOS Sierra 10.12.3 Update - Apple Support

I'm still seeing the same glitching on shutdown, but it's intermittent. I'll get several in a row, then several clean shutdowns in a row. I'm sitting on it for now, but once I get close to the end of my warranty period, I may consider taking it in.

Seems like Apple should be motivated to fix it before they get a [boat]load of expensive returns.

Yes, I'm: - Late 2014 -27inch -Core i7 -AMD Radeon R9

I haven't had the issue in a long time. Don't look for a pattern, it's probably a harmless software particularity that happens at random.

Apple ‘geniuses’ however should

• Be aware of the problem [how to be aware ? maybe by reading this forum]
• Stop replacing hardware to solve the problem. To stop a problem you must first of all be able to diagnose it. If you don't know what it is, maybe try a harmless cure like resetting pram, or safe mode & similar -probably won't work, but sounds exciting- medication, but don't cure it by operating.
• <I don't know> is a valid scientific statement, as any genius should know.

TargetCoder,

Very interesting. I had the issue on recently purchased:

• iMac (Retina 5K, 27", Late 2015
• 3.2 GHz Intel Core i5
• AMD Radeon R9 M390

But, does that mean your R9 M395 video card is better (or not defective)?

Techs don't seem to agree. Some say software. Others say it's the video card.