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

Hi Beolion,

I have a late 2012 imac, I can replaced the PSU from apple store due to the random shutdown issue. The computer was working ok, but the random shutdown happens again 6 months later. I am pretty sure Apple just replaced the Original PSU unit rather than getting an upgrade to resolve the problem.

When I reboot in 'safe mode" the problem seems to go away. Any things on this and how to pin point the cause?

thanks,

hank

Hi hank,

well thats the other side.

When it first started (the random shutdowns) it turned out to be Safari. Whenever I used Safari, I had this shutdowns.

Then I switched to Firefox and the shutdowns went away, not a single one for weeks but then it startet also when I changed the volume of the speakers or open the AppStore.

Since then I also think of a Software Issue - so maybe its the PSU, maybe the CPU but also maybe the Software...

Experiencing exactly same issue here... iMac 27 (late 2012) with 3.4Ghz i7, 32gb ram. The quirky thing I have found that there are no issue when I boot in the 'safe mode'.

This leads me to think that it is a software issue. I'm still working on it, do have replacement RAM coming from Crucial and call with Apple in the am.

Has anyone else had the same experience with safe mode?

Hank

I have a similar machine. Late 2012 i7 3.4GHz 32GB 680MX. I got my power supply replaced by Apple Store itself in Istanbul around 10 days ago. I never tried to replicate the shutdown problem in safe mode but I even got the shutdowns on the windows 10 partition and another partition that I created for testing purposes.

Apple Store itself of course couldn't replicate the problem like almost everyone else in here experienced. It's probably down to power supply not being powered on for far too long). But they still replaced the power supply for around 115 US Dollar (340 Turkish Liras)

By the way as far as I'm told it's a 300Watt part. While I was at it I asked them to fit the machine with some other type of power supply made for other, possibly newer iMacs that utilize a higher wattage part. They refused to do so. Apple policies obviously. I haven't asked about the brands of the outgoing and incoming power supplies. I'd do so if I had read the related posts in here.

Long story short, for the past ten days the machine has always been on, I had played Civ V for like 10 hours at once, max. settings and so far no shutdowns. So, tho Apple Geniuses failed to replicate the problem and tho it seems like a problem Apple itself should acknowledge and pay for, apparently the replacement of the PSU resolved the issue.

I just removed the 32 G of Ram for return to Crucial, and inserted the original 8 and now its working fine (so far)! Maybe the power supply has trouble with 32 g?

Imac needs Ram to be 1.35v, maybe your 32 gb were 1.5v. Might be what was making the PSU turn off

Thanks ngrant, good thought, but the spec is 1.35v from Crucial. Can the power draw go up with age?

HERE IS THE FINAL DEFINITIVE SOLUTION FOR THE PROBLEM!!!!

We have only one solution:

Apple have to replace the power supply unit with a reinforced/modified one

to all the owner have random shutdown.

They replace the PSU and for a variable range of time, users does'nt have the problem.

But the PSU is the same of the original one with the same problem...

Every one of us of this topic have to send a message to

Apple here:

http://www.apple.com/feedback/

This is a preferred way to comunicate with Apple Support.

this is a special channel that Apple consider with particular care.

at the end of the mail copy the link of this thread: https://discussions.apple.com/thread/6176570

so they can read that we are a lot of dissatisfied users.

I do agree with ElBartolomeo. I have just submitted the feedback form to apple as the bug report.

I hope all of us can follow ElBartolomeo 's suggestion and raise this issue. Obviously, this is a faulty PSU.

I can't even sell this iMac due to this issue.

Hopefully, Apple will provide the action and solution to fix the problem.

I Have already done . I lea a feedback in bartolomeos link

Very good.

Now ALL of us with this problem HAVE to do this.

and Apple HAVE to listen our problem.

It's clear that our series of iMAC but also the 5K

are faulty....

Apple HAVE to do something.

It isn't an our problem.

the iMAC are faulty from the factory....

And I want to remember that our iMAC are very expensive computer respect the hardware.

And we are willing to spent so much because we will expect high reliability that windows PC haven't....

otherwise our next computer will be a Window based assembled PC.

at least if it will breaks we fix it with little money....

Apple read with emphasis messages sent to their feedback system...

we must do all to give greater strength to our individual complaints

Well we have to wait and see whats happen...or not.

Thank you for your feedback on the iMac.

We cannot respond to you personally, but please know that your message has been received and will be reviewed by the iMac Team. If we need to follow up with you on your ideas for improving the iMac, we will contact you directly.

We appreciate your assistance in making the iMac a great computer.

iMac Team
Apple

I Have already came from the apple store and the y gave me for free a new cable for the iMac ( i am out of warranty) They didnt find anything in my iMac. I will share the results of the computer.