iMac (Retina 5K, 27-inch, Late 2015) Randomly Restarts Without Errors

Hey jdunderhill, how'd you convince Apple to actually replace your logic board? My iMac continues to do this restarting thing (killing my workflow) but the local Apple Authorized Techs, not Apple Genius Bar, I live in a rural area 2 hours away from the nearest Apple store, couldn't find "anything wrong" so I'm at an impasse––how do I get Apple to actually replace the Logic Board so I can get on with my work?

So, from an online chat to a call rom an advisor, who then passed me on to a senior advisor.

Listened to my whole ordeal, and after stating that seen as it has been in for a repair regarding the issue and a OS erase and reinstall didn't solve the issue it must be hardware related. I have to take it an hour each way back to the repair centre, so they can try diagnose / replicate / repair / replace. If i get it home and the problem persists I am to call him back to escalate the case. - to what I'm not sure, a new iMac hopefully 😝

FML.

They have absolutely no interest in even looking at this post , I'm sure theres something they could find useful within these posts regarding the issue.

Cheers to another two weeks with no iMac and not being able to work at home, 😀

Keep posting folks. Apple is now reading this thread. I got a call from Apple today because of all my posts here. I will let you know how the case gets resolved. Seems the right person has been awakened.

mrdgvb1, excellent news––I spoke to a senior Apple Rep today––it was a very long (almost 2 hour) conversation, and they used some sort of Capture App to get data on my Mac to be sent to be analyzed––hopefully it ends up being resolved in a solution where they finally have an answer (either replacing the Logic Board, or a permanent software fix)

Hello all,

It's been one week since my iMac had the logic board replaced and no errors...

So it looks like that fixed the restarts... I restored from a time machine backup...

It also seems to be faster than before with finder copies...

For other owners of iMacs from the Late 2015 line just ask for a logic board replacement.

I bought mine October 12th, 2015... I know of another owner with the same iMac bought in January 2016 no problems.

So the hardware error could be from a small production batch during that time...

- bl

Finally, please let me know what your outcome is, I can only take mine in on the weekend so if there is anything they give you that would help push for a logic board replacement ( if thats the solution ) it would be good to take it with me.

Hopefully they come through 🙂

24 hours of no restarts after new logic board and 10.11.5. Seems to be faster, too.

Updates folks––so the Apple senior advisor says the engineers think my 3rd party RAM (purchased through OWC, a respect Mac 3rd party RAM provider) is at fault.

This is similar to what others in this thread had to go through––a barrage of tests to get us, presumably, to the fix (a logic board replacement).

I will entertain this test after I finish up a video project (that really requires the 32GB of RAM I installed, versus the 8GB I ordered with my iMac) and see if the restarts still occur-–my guess is they will, and hopefully after that, this long, drawn out affair will be concluded with a logic board replacement.

After two months of working with Apple Support techs and getting nowhere, I received a call from Applecare Outreach this morning. Apparently there are enough instances of this issue that the engineers are now interested. So I'm hoping my next crash will finally provide some answers.

I hope the next crash brings you to a solution Vannter!

For the record guys, today, June 28th, around 11:40am, I put my Apple RAM (the original 8GB that came with the machine) into the machine in place of the CDW 32GB that I bought. I don't believe this will solve the issue (the machine has restarted twice this morning) but Apple wants me to follow this step.

If it restarts again, I believe Apple will have no choice but to replace the logic board.

I also received a phone call from Christina from Apple Outreach a little while ago. She was very pleasant, gathered a lot of information and walked me through gathering logs to send to them as I had specific dates and times that my machine rebooted over the past week. She is passing on the updated logs to the Senior Advisor that I talked to yesterday. When I spoke with the senior advisor I asked him if he was aware of this discussion thread and he wasn't so I sent him the link and asked him to check it out. It looks like he did since people have started getting calls today from the Apple outreach. This problem has certainly gone on long enough and I sure hope they are able to come up with a fix soon or at least replace our machines so we can get back to working with a very expensive computer that we can rely on.

Hey folks, update! At 6:41, my iMac (with the original RAM in it) froze and restarted. Same -128 error. We now know it is not the RAM!

I left a message with the Apple Senior Advisor I've been speaking with––hopefully NOW we can replace the logic board and get the same fix others have in this thread.

Wow, finally finding this thread (with tremendous assist from Linc Davis; thanks Linc) is a wonderful feeling. I have been dealing with this exact issue (same generation iMac, same exact problem) and been absolutely frustrated with Apple's inability to fix the problem (after 2 separate one-week periods of it in the shop); the techs clearly had no idea what was going on and in absence of any solutions they just shrugged and said, "huh, must be some software." After SCRUPULOUSLY combing through my computer, running a couple different diagnostic scripts (EtreCheck and Linc Davis's), I'm pretty sure no software is to blame. I'm curious if the logic board fix seems to be working for everyone; I'll call Apple and ask/demand that remedy if that's the case. I too have OWC memory but, again, no error messages at all point to RAM. Anyway, other than asking about Logic Board stuff, I'm really just voicing that I'm yet another user with this exact same issue and no remedy from Apple.

Just piling on here after being redirected by Linc Davis from another thread. Just going to add that I've had my iMac with this issue into the Apple Store and they could find no problems, but the issue continues. Note: I'm running a very stock system. Memory from Apple when purchased. No external devices connected. Like several other posters, this is an issue that has only come up recently (last few months), and not anything that was immediate when I purchased the system back last year.

My iMac is at Apple for the 2nd time now purchased Dec 2015... Restarted 10.11.4 It's been restarting since they "said" they fixed it... But I doubt they really did anything to it. So whenever they call me this time I hope they tell me they fixed the logic board or I'll disappointed again...

Really frustrating, when I get it back it will be about my 6th time re-loading all my programs on it. Only use it for work, and I can't even work with it. Using a macbook pro instead... 27" $2000 piece of junk in my opinion... It better start working, because there's absolutely no resale value for a computer that restarts randomly, all the time!!!

Please fix my iMac Apple !!!