iMac 27" 5K Late 2015 screen artefacts on shutdown

Same problem here with iMac Retina 5k 27" late 2015, Mac OS 10.12.2. Multicolor glitches on shutdown. As long as it's not causing wear and tear on the hardware, and doesn't happen while the computer is up and running, I can live with it. Not a very smooth job of integrating software and hardware on the part of Apple, though.

I've had power-supply problems with iMacs I owned years ago, and it crossed my mind that the display glitches could be a symptom of a power-supply issue, like power to the display spiking or glitching on shutdown. But from previous comments on this thread it sounds like more of a software or firmware problem. I'm not lugging the thing back to the store until it actually stops me from working on it.

I'll be keeping an eye on this thread.

God I hate logging in to these Apple forums on Firefox. It always takes 10 tries before I can post logged in. Anyway, in that the hardware glitches when used with any version of Sierra, if it is hardware related, it is likely a driver issue with these 15 imac cards since it reverses for those that have backed down to el capitan. My money is on a funky Sierra gen kext related to the vid cards. Yes thankfully the problem rears up only during a shutdown or restart situation. Doesn't seem to be any lasting damage. It's just kind of jolting to see.

Etuj,

additional info - Today I had call with Apple support (NL) wrt to two problem. They informed me that both issues (domino effect & coloured screen during shutdown) are acknowledged by Apple. They think its now HW related issue and they expect apple to release new update soon.

i7, M395X, 1TB SSD, 16GB RAM. It has happened a couple of times but never on El Capitan, in fact shutting down has not been smooth since Sierra came out. I'm inclined to think its software tbh as El Cap had none of these issues. Mine was bought January 2015 with Apple care and this only happened after Sierra install.

Hi community,

same problems with my late 2015 imac 27" running sierra.

I've allready got a brand new late 2015 imac 27" last friday and from the very beginning the shutdown generated this irritating 3-4 seconds during artefakts... just the same way as the first one.

I really hope that Apple reacts now as fast as possible.

Apple actually called me today to gather more information about this problem. The woman I spoke to told me they have been getting a lot of these reports (clearly) and they are fixing it. Hope it will be in the next update.

I, too, have 2nd iMac and it came with the same video card.

It arrived just last week. So, it's newly shipped.

It's doing the same thing the other one did - large bands on shut down, and it did it immediately, right out

of the box.

I did NOT have Office 2016 installed. I purposely did not install things to see if it did it without additional software on the iMac. It did it immediately.

27" iMac, 3.2GHz, i5, 1 TB SSD drive, 8 gigs RAM,

late 2015, 17,1

Just a bit of an update - I have had no issues for a few weeks now, absolutely nothing has changed and I do not use beta updates so I have no idea why it appears to have gone for now. I don't use it everyday, but when I do it is on for long periods, in that it will sleep - the sleeping part seems to be a common theme.

Of course, I spoke too soon and jynxed it. It happened again today again.

Anyhow, Apple called me again and I sent them extensive system diagnostics. It was a good thing it happened just now, because apparently it's easier to pin-point if you can tell them an estimated time when it occurred.

Bought my iMac (Retina 5k, 27", Late 2015. 3.3GHz i5, R9M395, 2TB fusion) in Sept 2016. Immediately updated to Sierra. Noticed artifacts when rebooting or turning off the machine. Took it to a local Apple Store. They did some testing and called me a few days later and told me they couldn't find any problems. They said we could replace the logic board because it sounds like it could be video card related. I told them to go ahead. Got it back a few days later and it was doing the same thing. A month later I decided to take it in again, but instead of the Apple Store, I took it to a local certified repair center that does warranty work. They had it for a week and did some testing and agin no problems found. We decided after a few more days to try another logic board and as of today, I have not had any issues with artifacts on reboot and / or shutdown. The iMac wakes from sleep more immediately now, too. I don't know if an updated logic board might have fixed my problem or something else, but Kudo's to Quadstar Digital Guidance for fixing my iMac. I was considering selling my iMac and going back to a MacBook. Never been so disappointed with Apple......

Don't panic and start swapping hardware. That won't help in the long run. This is an OS level issue that can probably be fixed easily once they figure out what they did to break it in the first place. In addition it seems to be harmless.

I bought it in Kings and already have changed it me 2 times on Monday take him and I train a new one in total have had three iMac and this will be the fourth.

I don't know if it is software or hardware it is to buy an iMac of over €3000 and it should work correctly I hope this works well.

Hi guys, sorry I don't know how to post a message, it looks like there's only the option to answer to one single person.

Anyway, I bought a new iMac in December 2016 and after one week it started showing this problem (I updated the operating system the first day).

I took it back to the Apple Store and got it replaced FOUR times because every time it had the same problem. Apparently no one there knew what the problem was. I wish they informed their staff of what's happening.

I've chatted with a guy at the Apple service and he told me it's a software problem and "they are working on it" and there's no point in me taking back the iMac to the Apple Store.

To be honest the problem hasn't shown itself in the last couple of weeks, actually... different problem this time: now (always when I turn it off) the screen becomes black line by line and slowly.

Since I've replaced it FOUR times in two months then I guess it's not hardware, how could that be?

Thanks.

New problem that you described seems to be so called 'domino effect'. I had similar issue. According to apple support team, it's SW/FW problem. I checked with another apple retailer and according to them, it's HW issue. I didn't wanted to take a chance. So I replaced my iMac (27" late 2015 model)

I'm having this problem too. This is not okay for such an expensive piece of equipment. I bought my iMac in Nov '16 and only started noticing the glitch last month, as I haven't been home to use it much.

iMac (Retina 5K, 27-inch, Late 2015)

Version: 10.12.3 (16D32)

Processor: 3,3 GHz Intel Core i5

Memory: 8 GB 1867 MHz DDR3

Graphics: AMD Radeon R9 M395 2048 MB

Anyone had any luck with returns?