iMac 27" 5K Issue.

iGeek2014

macrumors 68020
Original poster
Jun 29, 2014
2,113
1,093
=== Nowheresville ===
Hello there.

I'm having some issues with my mid-2015 iMac 5K.

Very recently it keeps shutting down of it's own accord. I have to unplug the iMac from the mains and wait a good few minutes before I can power it back on again.

I've spoken with Apple support and tried the Diagnostics test, a SMC Reset and even different mains sockets but it still persists.

I am booked in to the Genius Bar next Thursday afternoon and am hazarding a guess it's hardware related. As I'm out of warranty (it's a second hand iMac purchased via eBay and has been running fine since November 16) what kind of fees should I be looking at?

Thanks.
 
  • Like
Reactions: sboychuck

MrGimper

macrumors 603
Sep 22, 2012
6,448
6,946
Andover, UK
I've had this start happening with my 2012 27" iMac. Everything i've read points to a Power Supply issue. Will be running happily and then just power off. Have to pull mains, wait for 15 seconds or so, plug back in and press power button to boot. Effectively the machine dies and needs an SMC reset every time you want to get it back up.

I ran the Apple diagnostics overnight and the machine was still up this morning, showing no diagnostic errors, so perhaps it's power load related. Be interested in what you get from your visit.
 

MrGimper

macrumors 603
Sep 22, 2012
6,448
6,946
Andover, UK
Any chance you guys are running the iMac via a surge protector or similar.or an extension lead?
Nope, I've tried several sockets in the house and several power cords

Edit: I'm now trying to install Sierra from a USB stick onto an external TB SSD. Hopefully if that works I can at least to a SuperDuper clone of my internal Fusion Drive to another HD "to be sure, to be sure". I'll then see if it runs from the external. Hell, I'd be happy if it ran long enough to do the install!
 
Last edited:

todds89

macrumors newbie
Sep 1, 2016
8
0
Same issues here... started about a year ago, then quit for about 6 months. Now starting to do it again.. just shuts off randomly, doesn't even seem to be load based. Have to unplug for UPS and then back in.
 

MrGimper

macrumors 603
Sep 22, 2012
6,448
6,946
Andover, UK
Install worked but switched off shortly after booting from the external disk. I've now ripped out 3 of the 4 SODIMMS and trying again.....
 

PhoenixDown

macrumors regular
Oct 12, 2012
177
98
Happened to a friend's 5k iMAC ... computer would randomly shut down.

Turns out it was the logic board. But this was after they replaced the SSD portion of the hybrid drive.

Thankfully covered under Apple Care but it was serious $$$.
 

chscag

macrumors 68040
Feb 17, 2008
3,740
1,293
Fort Worth, Texas
Happened to a friend's 5k iMAC ... computer would randomly shut down.

Turns out it was the logic board. But this was after they replaced the SSD portion of the hybrid drive.

Thankfully covered under Apple Care but it was serious $$$.
Any work done out of warranty on the "glued together" iMacs is going to be expensive. Mine is also out of warranty and I'm hoping it holds together long enough until the new iMacs appear and I can trade up. :rolleyes:
 

MrGimper

macrumors 603
Sep 22, 2012
6,448
6,946
Andover, UK
Mine died again, but I have just used an air duster on the air intakes on the underside, and used a vacuum on there too as well as inside the memory door and rear exhaust vent. LOTS of dust flew out of the air intakes below the screen. Fingers crossed, touching wood (ooo-errr) etc, it's been up and running for 90 minutes doing a disk clone.....
[doublepost=1495484747][/doublepost]And it died about 15 mins after my previous post...
 
  • Like
Reactions: PhoenixDown

iGeek2014

macrumors 68020
Original poster
Jun 29, 2014
2,113
1,093
=== Nowheresville ===
Sorry for the delay in replying to my original post.

I had been using a UPS but have tried other (main sockets) and it still persists.

At the moment I've been using it for an hour or so a day then shutting it down altogether when it's not in use.

Although it's been out of warranty since June 2016 (according to the model's details on my Apple I.D) I'll see what they say come Thursday.

Did check the air vents for any dust build up but there was nothing.

Granted I didn't purchase it directly from Apple but if it was the Logic Board I might exercise my consumer rights.

Fair enough if it was getting on but a computer that was originally £1,599 and just under two years old that's been looked after shouldn't fail so easily IMHO.

In all fairness to Apple a few years ago the LCD panel on my iMac 21.5" mid-2011 failed and they replaced it under the SoGA.
 

PhoenixDown

macrumors regular
Oct 12, 2012
177
98
@MrGimper -- Try booting your iMac from an external drive. If that seems to work for an extended period of time it may be time for a new drive. If that doesn't work, then its likely your logic board. :(
 

MrGimper

macrumors 603
Sep 22, 2012
6,448
6,946
Andover, UK
@MrGimper -- Try booting your iMac from an external drive. If that seems to work for an extended period of time it may be time for a new drive. If that doesn't work, then its likely your logic board. :(
My last attempt was booted from a clean install of Sierra on an external Thunderbolt SSD :(
It ran for about 100 minutes, doing a super duper clone of my internal disk to another external USB disk.

Strangely enough, it stayed up during the install and also overnight when I ran the in-built diags.

Annoying
 
  • Like
Reactions: PhoenixDown

Lightsaber

macrumors member
Jan 10, 2015
60
76
My last attempt was booted from a clean install of Sierra on an external Thunderbolt SSD :(
It ran for about 100 minutes, doing a super duper clone of my internal disk to another external USB disk.

Strangely enough, it stayed up during the install and also overnight when I ran the in-built diags.

Annoying
Could be a bad memory stick.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.