27 iMac (2012) crashes and requires smc reset to turn on

I'm replying here because @ElBartolomeo posted what I wouldn't consider an inaccurate supposition, and in which also including a link to a post that I created /started YEARS ago. I don't think there's just one thing with the iMac. It's never been that, and never was with two of mine. I believe - there's something more inherent in the entire iMac line- from the very first version of the i3/i5/ i7's.

I had one of the very first 27", i7 iMacs. In fact, I had to preorder it and then - I still ended up having to wait an extra month. I've had a second one since then. Mine has an optic drive, which the newer ones don't and have additional, optional configurations, but it would seem Apple still hasn't figured out the issue that plagues the iMac.

As a former Apple employee I know Apple will never call anything a - - "recall." They generally refer to a recall situation as a "repair extension programs" and they will always have those listed on their site, typically in the support area, and I don't believe they ever have with any of the iMac (intel) models, including 5k. Unless someone can provide a knowledge base number of an extended repair program - @ElBartolomeo is incorrect on several things.

There is **NO** 'definitive solution' and to say so would be misleading to people. It's not necessarily a power supply issue, and definitely not just a SMC issue. I had two iMacs with this issue and Apple threw every part they could at both of them (except the power supply) Apple ended up replacing my first, and the second is finally working, however it still gets extremely hot, which is one of several side issues.

But no firmware (SMC) or power management resets ever fixed the issues, and I never received a new power supply, nor any modified one. In the couple of years of receiving my replacement Apple in fact may have changed their approach to the issues they've had, but I'd to see an Apple notification on their site of this.

Otherwise, as a former Customer Relations employee, I can tell you they approach every situation on an individual basis. There's no ... "one" solution as has been implied.

Now I admit - it's been (only) a couple years, but Apple could have changed their approach to this situation, but then again - I would ask you to provide an actual Apple post showing this. It can be a pain, and I was painfully reminded myself of the "individual process" when I had to jump through all the Apple hoops, TWICE, for both of my iMacs.

Providing either of the links to Apple feedback is not a preferred way to speak to support. In fact - it's merely a method of providing general feedback to Apple. You'll be lucky if you get ANY response through that method. The best method Apple tech support (of course - better if you have AppleCare or still in warranty)

The next best resource is to get Customer Relations involved, and oddly enough, you'd be surprised how well an Apple Store will help. Combine all three, and try to keep case numbers to a minimum if not one, and /or consolidated. But you're going to get more action by talking with someone rather than through a feedback form in which you most likely will never hear back from anyone.

Opps, its doing it now with the 8G. But strangely after 4pm, or 120f on the CPU.

thoughts?

FWIW, I went ahead and ordered a new power supply on Ebay for $55 and did the replacement myself. Computer has been running without random shutdowns for 2 months now. Previously, I was getting anywhere from a few days to a week before the computer would crap itself.

I'm not a trained technician, but I've hacked into things like this before so I was confident in my abilities (plus I was desperate since my $3500 computer was a useless pile of junk due to the shutdowns). YMMV on confidence/abilities.

Note, hacking into the iMac will void your warranty but if you're considering this, that probably means you're off AppleCare anyway. If not, go through the process and have Apple to do it.

Risks summarized:

• Electric shock?
• Straight up breaking something inside the computer if you're careless?
• If Apple ever comes around and issues an official recall, or starts replacing these with a newer model (don't hold your breath), this will probably screw your chances.

In closing, I doubt this will be a permanent fix since others have reported that shutdowns eventually return, but at least it buys me some time. If I can keep this thing running for another 6-12 months, it's still better than the $3500 brick that was previously on my desk. If it lasts longer than that before crapping out again, I'll do another power supply replacement to extend it even further. For my purposes (photo editing, light video editing, and web browsing), this computer should last me another 3-4 years (6-7 in total), so my best case scenario is that if each power supply replacement buys me 12-18 months, I would have to do another 2 power supply replacements to extend this thing to a 6+ year lifespan. I'm okay with that -- not terribly happy, but still -- better than tossing $3500 in the garbage after 3 years.

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Thanks for this. I hope you have resolved the issue - but only time will tell. It reminds me of the Dual USB IBook power chip failure that involved a compromised solder joint on a pcu - well documented worldwide. This issue was contested by the Consumer Rights body in Denmark who won a legal challenge against Apple resulting in replacement

of failing IBook laptops. This is clearly a production error, as yet unresolved - despite the above replacement solution - which I hope will be conclusive. I am not holding my breath, however.

@ohmyggg

Can you make a picture of your old power supply and put a link here ?

It would also be interesting to know what manufacturer and what revision your old PSU was.

Do you know the revision of your new PSU? It is a Liteon I guess?

Power supply is from Liteon, you can grab it on ebay

http://www.ebay.com.au/itm/New-Original-2012-27-iMac-A1419-300W-Internal-Power-S upply-661-7170-PA-1311-2A-/271887305639?hash=item3f4dbf0ba7

I've bought one, will install it when it gets here and let you guys know if it solved my power off issues....

What power supply is/was standard delivered with the 2012 model?

ohmyggg wrote:

FWIW, I went ahead and ordered a new power supply on Ebay for $55 and did the replacement myself. Computer has been running without random shutdowns for 2 months now. Previously, I was getting anywhere from a few days to a week before the computer would crap itself.

I'm not a trained technician, but I've hacked into things like this before so I was confident in my abilities (plus I was desperate since my $3500 computer was a useless pile of junk due to the shutdowns). YMMV on confidence/abilities.

Note, hacking into the iMac will void your warranty but if you're considering this, that probably means you're off AppleCare anyway. If not, go through the process and have Apple to do it.

@ohmyggg -

you guys all seem confident the power supply is the long standing issue? I asked here before for an official Apple link indicating the issue, but no one's replied. Is there some documented of Apple admitting a problem?

I'm not trying to cause grief, but suggestions, as I've been through this issue twice, with my first one being replaced, and the second one basically being gutted with all new parts. One issue was there was an actual recall for a certain video card which my second qualified for. But in all - my power supply for both my iMacs were never replaced.

As for doing repairs yourself - the real pain in the but is the awkwardness of working with the all-in-one iMac, and then keeping the inside of your display, and the inside of the glass cover clean and clear of any particles. My second Mac had it's parts replaced with an on-site repair. I was fortunate because I was able to watch over the tech, and secondly; he was a part time photographer and graphic artist so he, himself was picky how the screen looked.

I digress: Seeing how you're convinced this is a power supply issue - you've probably already purchased your power supply? It didn't sound like you were afraid of hacking into the iMac, but I would encourage you to still try with Apple. I use to work with Apple CR. Get through to Customer Relations and straight up... ask for a warranty exception (for whatever you want to try) - especially and primarily if you already have repair history, or documented discussions with Apple (cases)

Have them look again, or have them do the repair - if they will. It's also still possible to find AASP's (Apple authorized Service Providers) They all have their hourly rate, and sometimes have jobs already marked hourly of how long it will take. Sure... it may cost $100 - $200 to repair (I think that's on the high side) but... if something gets screwed up - THEY'RE on the hook for the cost. If there's dust under the screen, or something not working right afterwards - they, again are on the hook. Just depends on how much you think your time, and possible future issues are worth to you.

just my 2¢

I still am curious to know of any documentation point to the power supply being the issue?

I have been suffering with the same issue since Nov 2015. After 4 repairs and 4 failed attempts by Apple to replicate the issue, they have FINALLY make a breakthrough and replicated it.

They informed me they replicated the shutdown during an "extended memory test" of the RAM chips. My original build was supplied with 8GB RAM and I added another 16GB myself. The store switched in and out new and old chips but the issue still occurred. The average genius in an apple store won't know how to remedy this.

A referral to Apple Engineering ensued and they recommended "switch the logic board".

My advantage here was that I already had the logic board switched about a month ago - and the issue remained.

By this point I had the apple store manager involved and on my side.

The recommendation from him (and his Genius team) was that switching the logic board wouldn't resolve, so he would authorise a replacement machine.

So my advice to you is persist - replace the hardware they recommend, and if that fails - the manager of the store can authorise a replace but the whole process has lasted about a year. I sat in the store today and listed off all the things I had tried:

• New 3TB Fusion Drive x 2
• New Logic Board
• Old / New RAM
• El Capitan (from restore)
• El Capitan (from new)
• HDD wipe and reinstall original OS X (Mountain Lion)

What also really helped was videos I took which captured the behaviours of the random shutdowns. This gives you evidence when apple technical support tell you they can't replicate the issue.

Hope this helps.

I started one of the very first strings SIX years ago on all these issues (27-inch / 27" iMac Random Shut down) which included a possible issue with RAM, heat, SMC, a weird video interruption screen, random shut downs and restarts, random shut downs with black screen but power remained on.

I experienced ALL of the issues on my first iMac, and none of the "supposed" fixes corrected my iMac including SMC reset. One of the most popular, but unconfirmed suspicions was RAM - even six years ago, but I was convinced it was not. People mentioned the issue at 8gigs, some mentioned at 16gigs, and I had both, switched them in and out with brand size, and it didn't matter.

I agree with @C4MEL - go for having Apple to replace components. Apple, however won't start talking replacement until the a 3rd repair is done, and you're looking at your 4th. FURTHERMORE - I strongly suggest NOT doing more than one component per repair. Apple almost screwed me over by replacing 2 -3 components in one repair, which would normally have been done in separate repairs. They nearly considered the repair only as ONE, and even though I had been going through issues for more than 1 ½ years.

I too ordered a power supply from E**y for $65, and I am having it installed tomorrow. The funny thing is, like others have stated, if I unplug the computer overnight, or at least 2-3 days at a time, I don't experience any shutdowns. But if I leave the computer on for about a week, then I have the shutdowns. It's strange how by just unplugging it overnight puts the shutdowns at bay, why? I don't understand it honestly, but like I said, I am having the power supply changed tomorrow and I will keep you posted. The only thing is so many other people have had the power supply changed and the shutdowns came back eventually. I tell you, I just don't understand it. I also read online that people have been suffering with these random shutdowns for years with previous macs as well, not just 2012 and up. At any rate, this is my last attempt at paying to have something changed in this mac, if this doesn't work, I will result to the unplugging thing for a while, and eventually by a new computer down the line. But I am really tired of dealing with this issue as the rest of you are as well I'm sure. Stay tuned......Ugh!!!!!

Hmm, is there a way to PM on this forum?

Mods edited out a lot of the information I included in my post about the power supply repair.

To address some of the other questions, I had included a link to the specific power supply replacement that I purchased but the mods removed it.

It's a 300W power supply and the Model # is A1419. It also goes by Apple Part #: 661-7170

I also included links to the other things you'll need (guitar pick, spudger, adhesive strip kit, and torx screwdriver) but that information was also removed by mods.

Anyway, with a little digging around, you should be able to figure out what you need and where them. Total cost was about $85 and the repair takes an hour.

And someone asked about dust particles getting lodged between the glass and LCD. This will NOT happen on the late-2012 iMacs because the glass and LCD are bonded together. When you do the repair, you're removing that entire front assembly (glass and LCD) so there is no risk of dust getting in between there.

in the last days, I've tried to unplug imac in the night.

and in the day after no shutdown occours, with simple use: word, safari....

I've to try with long video rendering now... because in the last months this ever shutdown my imac.

Stay tuned.

(if it occours, i'll buy new power supply on ebay. I now that it will not be a solution for ever. but 60$ for some year for me is a good solution. My imac was 3750€!!! (2012))

i'm watching that there is two or more version of PSU.

the common liteon one:

http://www.ebay.it/itm/Apple-27-iMac-A1419-MD095-MD096-300W-Power-Supply-Board-6 61-7170-PA-1311-2A-/171549612912

http://thmb.inkfrog.com/thumbn/sjinmin/15131_6.jpg=550

and another one (this one have more efficient and additional heatsink...):

http://www.ifixmaccomputers.com/661-7170-apple-power-supply-imac-27inch-late-201 2-a1419

http://www.ifixmaccomputers.com/image/cache/data/661-7170-500x500watermark.jpg