Uh oh...black screen on new late 2015 iMac

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
Was switching between users on my brand new Late 2015 5k retina iMac and the screen went to black. Nothing but a hard restart would bring the machine back to life. A long press on the back button shut it down, so I know it was still on. Another long press brought up the Apple logo and the start-up chime. That was about 4 hours ago and the black screen hasn't returned...yet. I fear if it's happened once it's just a matter of time before it happens again.

An online search for the problem brought up loads of similar experiences for past iMacs, but I haven't been able to find anyone else reporting this for the late 2015 iMacs.

I have a Retina 5K, 27-inch, Late 2015; 3.3 GHz Intel Core i5; 16 GB 1867 MHz DDR3 (8GB bought from Crucial); AMD Radeon R9 M395 2048 MB; running El Capitan 10.11.1.

I've never seen so many ideas out there about fixing the problem. It runs the gamut from wipe hard drive; reinstall software; get a new video card; unplug everything and plug it in again; try a different keyboard; unplug Time Machine; reset PRAM; remove new RAM, and many many more. I'm not ready to do anything until it happens again, but just wondering if it's happened to anyone else with a late '15 iMac.

Thanks!

P.S. And of course it happened on day 15 of ownership, so an easy return probably not in the cards. :rolleyes:
 

whodatrr

macrumors 6502a
Jan 12, 2004
672
490
Was it a black screen that still had a cursor?

Happened repeatedly with my new 5k, but within the return period. Ultimately, I wound up returning it on the advice of Apple. But mine may have been different than yours, as it sounded more severe.
 

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
Was it a black screen that still had a cursor?
I had read about the black screen with cursor from others' experiences, but I honestly don't remember seeing the cursor when I tried to wake my screen. It might have been there, but I didn't notice it before restarting. If it happens again it's one of the things I'll look for, since it could be a key to the problem. Thanks for asking.
 

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
You could try running the built-in diagnostics test.
Restart, while holding the D key.
Run the test.
Check for errors when the test completes.
Thank you so much for this suggestion. I had forgotten that Apple had a built-in diagnostic test, which is really quite wonderful to use when you're questioning your hardware. I ran the test and received a "No issues found" message. That's a bit of a relief, but will only go so far if the black screen returns at a later date. Time will tell.
 

rkaufmann87

macrumors 68000
Dec 17, 2009
1,760
38
Folsom, CA
Was switching between users on my brand new Late 2015 5k retina iMac and the screen went to black. Nothing but a hard restart would bring the machine back to life. A long press on the back button shut it down, so I know it was still on. Another long press brought up the Apple logo and the start-up chime. That was about 4 hours ago and the black screen hasn't returned...yet. I fear if it's happened once it's just a matter of time before it happens again.

An online search for the problem brought up loads of similar experiences for past iMacs, but I haven't been able to find anyone else reporting this for the late 2015 iMacs.

I have a Retina 5K, 27-inch, Late 2015; 3.3 GHz Intel Core i5; 16 GB 1867 MHz DDR3 (8GB bought from Crucial); AMD Radeon R9 M395 2048 MB; running El Capitan 10.11.1.

I've never seen so many ideas out there about fixing the problem. It runs the gamut from wipe hard drive; reinstall software; get a new video card; unplug everything and plug it in again; try a different keyboard; unplug Time Machine; reset PRAM; remove new RAM, and many many more. I'm not ready to do anything until it happens again, but just wondering if it's happened to anyone else with a late '15 iMac.

Thanks!

P.S. And of course it happened on day 15 of ownership, so an easy return probably not in the cards. :rolleyes:
Don't waste your time, you have 90 days of free AppleCare telephone support, call them immediately.
 

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
Don't waste your time, you have 90 days of free AppleCare telephone support, call them immediately.
Very True! I gave them a call today and we basically went through the diagnostic test again and it came back clean a 2nd time. They really didn't have a solution for me, especially for a problem that's only happened once and hasn't returned yet. She suggested it could be a number of things, including a software glitch. I now have a case number in the event I need to contact them again.

Obviously I'll be on the alert for any black screen occurrences, and will update this thread if anything happens. Plus we'll see if this problem pops up for other new users of the Late 2015 iMac, since so many people are just now getting their machines.
 

Tantris

macrumors newbie
Nov 29, 2015
5
0
San Francisco
Was switching between users on my brand new Late 2015 5k retina iMac and the screen went to black. ... :rolleyes:
Same here! Retina 5K, 27-inch, Late 2015, 4 GHz Intel Core i7 was running fine for the first two days, then suddenly, while doing nothing special, the screen went black today, except that the cursor was still visible and still responded to the mouse. Only a hard reboot restored the machine to normal. I too did the diagnostic test right afterward [hold D while restarting] and found no problems.
 

Tantris

macrumors newbie
Nov 29, 2015
5
0
San Francisco
Just curious OP are you on an SSD or fusion drive?
Yes, I have a 3 TB fusion drive and AMD Radeon R9 M395X 4096 MB graphics card. Also, in case it could be the culprit, I should also mention that I have added 16 GB of Crucial brand RAM to Apple's original 8 GB for a total of 24 GB. [To save hundreds of dollars compared to Apple pre-installing it.]

I had researched the Crucial memory carefully in Amazon reviews and elsewhere, and people who had added it to a Late 2015 iMac like mine had NOT encountered any problems. Still, I suppose I could be unlucky and just have a bad batch. But could this produce a symptom like the black screen with cursor?

The black screen has not returned as yet---still only a single, mysterious occurrence.

THANKS FOR ANY HELP getting to the bottom of this. I'm using it as my main machine for mathematical research and writing, and cannot afford to have it go bonkers on me.
 

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
Just curious OP are you on an SSD or fusion drive?
I have the 512 SSD on my machine. It has now been 3 weeks since I posted the black screen incident and it hasn't happened again, so hoping it was an isolated incident. Tantris, one thing we have in common is the added Crucial brand RAM. I added two 4GB sticks for a total of 16GB. If the RAM is bad or somehow the culprit I feel like we'd have more issues than one blackout.
 

Tantris

macrumors newbie
Nov 29, 2015
5
0
San Francisco
...one thing we have in common is the added Crucial brand RAM. ...If the RAM is bad or somehow the culprit I feel like we'd have more issues than one blackout.
Agreed: I once installed bad RAM in an old machine, and it crashed constantly, so I DOUBT that could be the problem now, but I'm no computer expert, which is why I was hoping someone on this forum might be able to shed some light on these rare black screens. NOTE: Still no recurrence of the black screen for me. I'm cautiously optimistic, given that JohnSFO himself has now gone three weeks without another occurrence of the black screen. But I don't like mysteries!
 

Gmaster

macrumors member
Nov 8, 2005
46
0
Florida
Tantris and JohnSFO, Thanks for the updates (no return problems).
I've ordered Crucial RAM [DDR3 1866 (PC3-14900)], and I'm hoping for no problems.
 

fob

macrumors member
Sep 11, 2015
87
45
I would say it is most likely due to the crucial RAM. Did you get the Crucial Ram that was designated for the late 2015 iMac(released recently)? If not, check crucial's CAS Latency. The late 2015 for the iMac uses CL13 ram. AFAIK there are two or three CL ratings of crucial's sodimm ddr3 1866MHZ ram. Crucial Ballistics Sport CL10, a generic CL13, and the officially supported late 2015 iMac CL13 version. Make sure CL ratings match. Dont mix.
 

twilexia

macrumors 6502
Oct 16, 2015
282
57
I got the black screen (kernel error) twice on my 3tb fusion drive in one night. I think it was because I had 3 USB Hard drives plugged in, although not sure why that would overload the system.
 

JohnSFO

macrumors regular
Original poster
Jun 10, 2010
125
28
I would say it is most likely due to the crucial RAM. Did you get the Crucial Ram that was designated for the late 2015 iMac(released recently)? If not, check crucial's CAS Latency. The late 2015 for the iMac uses CL13 ram. AFAIK there are two or three CL ratings of crucial's sodimm ddr3 1866MHZ ram. Crucial Ballistics Sport CL10, a generic CL13, and the officially supported late 2015 iMac CL13 version. Make sure CL ratings match. Dont mix.
Got the CL13, DDR3-1866, and even went with two more 4GB sticks so things would match up nicely. I personally don't think it's the RAM. I'm betting on software glitches with El Capitan and hoping things improve with the next update. My black screen happened while switching users. Sometimes when I switch the cursor doesn't automatically appear in the password box. Also, what used to be a smooth, visually appealing transition between users is now buggy. The screen flickers before presenting the last screen. Sometimes it just switches to the screen saver already going. Weird stuff. I've sent feedback to Apple about it. Seems like once they have everything de-bugged in their OS they're already introducing another CA landmark and we start all over again. :(
 

Tantris

macrumors newbie
Nov 29, 2015
5
0
San Francisco
Got the CL13, DDR3-1866, and even went with two more 4GB sticks so things would match up nicely. I personally don't think it's the RAM. ...
Thanks, fob, for pointing out the mismatch between the CL13 rating of Apple's original RAM and the C10 rating of the Crucial Ballistix Sport memory I installed. However, several people on Amazon have mixed this CL10 Crucial memory with the existing Apple memory and have reported good results.

Further evidence that the RAM is likely NOT the culprit is the fact that JohnSFO was smarter than me and installed the correct CL13 RAM, and yet he experienced the original black screen that launched this discussion.

UPDATE: My mixed-CL machine has still not had another black screen (or any crash of any kind), so I'm keeping my fingers crossed that I can go for weeks at a time without problems, as JohnSFO has done.
 
Last edited:

PhillipJ

macrumors newbie
Apr 11, 2014
20
2
Denmark
How is your black screen working out?
My new late 2015 Imac just started yesterday doing it. It does it every time it should go in sleep mode, I just can't wake it unless I do a hard reboot.
How ever I used airplay yesterday too, and on my tv screen it worked, but my Imac just had black screen.
 

DeltaMac

macrumors G3
Jul 30, 2003
9,525
2,298
Delaware
How is your black screen working out?
My new late 2015 Imac just started yesterday doing it. It does it every time it should go in sleep mode, I just can't wake it unless I do a hard reboot.
How ever I used airplay yesterday too, and on my tv screen it worked, but my Imac just had black screen.
Seeing that others have this problem, too - so call AppleCare. If you are within your return period, then that will be easy. Or, repairs within warranty, too.
 

PhillipJ

macrumors newbie
Apr 11, 2014
20
2
Denmark
Seeing that others have this problem, too - so call AppleCare. If you are within your return period, then that will be easy. Or, repairs within warranty, too.
I just talked with someone from Applecare, she told me to install OS X again. It just finished. :) I'll test it so see if it works.
 

Tantris

macrumors newbie
Nov 29, 2015
5
0
San Francisco
UPDATE: It has now been more than a month since my first and ONLY black screen. I'm naturally delighted that the black screen has not returned, but I continue to monitor this thread for insight into the cause.
 

PhillipJ

macrumors newbie
Apr 11, 2014
20
2
Denmark
It is still new... you should simply return it or just call Apple Care?
It is new.
I tried:
Shutdown and remove all cables except the keyboard/mouse. This includes the power cable (most important)



Press and hold the power button for 5 seconds. This resets the SMC (If your Mac doesn't sleep or wake when expected - Apple Support)



Reconnect the power cable and press the power button and immediatly hold down the Alt-Cmd-P-R to reset the RRAM. Wait for the startup chime and keep the keys pressed until the second chime is heard.


I haven't got the black screen yet.
 

WhatAmI

macrumors 6502a
Sep 2, 2009
919
10
I just talked with someone from Applecare, she told me to install OS X again. It just finished. :) I'll test it so see if it works.
I had the same issue and a (non-destructive) re-install of OS X solved it for me