27' iMac (2011) Screen turns off

Temp Solution:

Reset your SMC and Pram.

Interaction and explanation here:

http://thenextweb.com/lifehacks/2010/12/04/how-when-why-to-reset-the-pram-smc-on -your-mac/

In my opinion if the SMC has issues, this should be considered and engineering problem and the fact it stops doing it's job

speaks mounds that it is an engineering problem, either hardware or software related and not connected to the user. So therefore

the repair should come in at the cost of apple beings there is nothing we can do as users to know what the problem is and fix it.

Thus giving the lengthy posts here about the same problem over and over again.

Sorry to ask but has anyone at apple even shown that they care and stepped into this forum to lend a hand and get you people up and running again?

I lean to "NO" .

So here I am, someone who cares about whats happening and giving it a voice!

I hope with my endless efforts into searching for a solution, that this one at least fixes the problem until you can bring your iMac in

to one of their genius bars and get told a cut a paste answer that diverts apple's accountability over onto YOU, the end user, and you

get to pay for the repair. Remember, just because they say it is a hardware problem, doesn't mean it's your problem.

(Like why have they not fixed this blatantly obvious issue?)

I have been BLANK SCREEN free since I have installed SMC Fan control (turned up my fans) and reset my Pram and SMC.

SMC Fan control only worked after the SMC was reset, nothing before then even though I have restarted my computer many times.

Hope this post helps.

@LexXXus69:

First off: cut down on your ranting. Your credibility might improve.

Secondly: there are a number of different types of the screen blacking out, like the backlight failing or the whole screen. There are also several possibilities of why each problem might be.

On my Mac it can run fine for three weeks or go down every few seconds. It started after the hard disk was replaced, and I can see that it is the backlight failing, not the screen. It also works fine with an external screen so for me it is not an SMC issue either.

So your "very simple math" is just not sufficient.

Thirdly: there are not THOUSANDS affected but at best a few hundred people out of MILLIONS who bought iMacs. "Suggs" to be one of them (and I do have the screen blacking out on my 2009 iMac) but that error rate is still much lower than for other computer manufacturers, so keep things in perspective. Exaggerating and screeming just peeves off everyone, even those who are affected too (like me).

@MarkusWinter

Sorry, I wasn't asking you to be my mentor on how to act on the net. I'm well off in that aspect being on my way to 50.

I'm old school Son.

When you have been dished out cut and paste answers as much as I have, you tend not to just post a simple complaint any more.

I'm a critical thinker, so I just don't accept an answer that doesn't equate out in the end given my EXTENSIVE knowledge and education of

electronics repair.

I will however conduct myself in the way I feel suits my needs and I definitely don't need or asked for you to come by here and try to "MODERATE"

my post. If you have nothing positive to add to this post then don't even bother. We are all here to complain about how apple is not stepping up

to this very serious issue of a very possible engineering flaw, starting with this problem that the OP posted.

If you feel the need to be Net Nanny, please find another thread to personally attack people.

Me personally, I don't care who you are or what your issue is. So if you have the same issue as listed and reported here, then by all means

CONTRIBUTE SOMETHING POSITIVE. If not, be the silent observer.

I'm here to bring a change to this problem that has been persistent for years. And it's not just hundreds, it's thousands of people all over

the internet, not just this forum. I'm trying my best to stand up and give this problem a voice. Stop trying to bring shame to this mass effort.

Everyone here has been knocking on the door of apple with little to no results.

I'm here and I'm banging on there door until someone answers and I'm making as much noise as I need to!

I'm here to get results MarkusWinter, are you?

If you are, pipe down and back up the peoples's voice so we can get our faulting iMacs that we paid way to much for the reputation of being reliable and stable.

You shouldn't attack someone that is trying to protect your financial interests when purchasing your faulting iMac.

This is not just small money to some people and you have to realize that and respect that.

So think about it, if the system is having an SMC issue then the blame is on apple because I guarantee that there is nothing the "Basic" user has

control of to stop and avoid heat issues and this can definitely cause heat damage and degrade the life of the electronics inside. And yet, this iMac has

had this issue for years with no resolution (since 2011). 3 years of a $5000+ iMac running fine and just turning off when ever it feels the need.

I'm surprised you can't feel my frustration through the lines of the net.

Any ways, Keep on topic please people.

Keep this ship steering in the right direction.

HA! Well, I'm OVER 50, "Son", so a big LOL ;-)

Critical thinking starts with oneself. If you can't take constructive criticism and are not willing to question your own beliefs, assumptions and convictions then you are no critical thinker. Simple as that.

Btw I'm a Scientist, working in Cancer Research, so I'm well aware of the issues involved in critical thinking. I'm also a programmer (self-taught), have assembled and repaired over 700 computers, and am quite proficient in disassembling my iMac and my MacBook Pro. Your "simple maths" simply doesn't add up, and you can't shoehorn a plethora of possible causes into one solution. There's no magic pill in Cancer Research, and there is no simple solution to the different causes for the screen blacking out on some iMacs. it might be a corruption in the SMC for some, but certainly not for others.

The top model of the 2011 27in iMac sold for $1999. Your model sold for $1699, plus whatever your memory upgrade was. A long way from $5000. Don't exaggerate, stick to facts.

if the issue happened since 2011 as you claimed, well within the warranty period, then why did you not take the iMac back?

And people come here for help and advice, not to read rants.

Personal attacks don't impress anyone, they just reduce one's credibility.

This issue started with me a few weeks ago and I have been slowly trying the various suggestions with no luck.

I have a mid 2007 iMac 24" that is doing the exact same issue. I have owned this iMac since buying new in Feb 2008 and it has been a workhorse. I have upgraded RAM and switched to SSD. It is currently running El Capitan and acts as my media server running Plex with an attached Drobo.

iMac ran great for several weeks after upgrading to El Capitan then I noticed that it wouldn't wake up. Did a hard restart, it ran great, and then black screen after about 20 minutes. I tried using screen sharing so I could troubleshoot from my laptop. Screen sharing works fine when the iMac's screen is working, but screen sharing stops working when the iMac goes dark.

Plex continues to run flawlessly while iMac is dark.

Has anyone tried hooking an external display to the iMac while it is black? I'm curious if I could hook this up to my TV.

Going to try adjusting fan speed next. If that fails, I may try a fresh install.

It's the other way round. YOU need to try an external monitor. If there is a picture on the external then you can exclude the graphics card as a culprit, but if there is no picture then the graphics card is probably toadt.

my iMac works fine with an external monitor, but in my case it is the backlight which is flaky.

Nobody else can make that determination for you.

+1 on this (or similar issue). I've even tried installing el capitan from scratch and the screen goes blank or dark or white and I get freezes.

I'm trying to see if running long term (days) on safe mode will stop the problem from occurring. Has anyone on this thread tried long term safe mode for this?

Actually, it's not. The whole point of these forums is to collaborate and find solutions. I'm not going to buy an hdmi adapter without knowing whether anyone has had success. Does someone else's success guarantee it will work for me? No, but it is a good sign.

So somebody (like me) can use an external monitor. What does that tell YOU? Right, absolutely nothing. Because you don't know if he has the same underlying problem or not. So you are back to square one.

You want a degree of handholding and dertainty that simply doesn't exist.

And you don't need to buy, just borrow from somebody (bring your iMac there to test).

Whoa...did not expect to get trolled on a support forum. Easy fella, just looking for ideas to try. That's the whole point of this thread.

Anyway, back to troubleshooting.

• Latest El Capitan update - didn't help
• Added a temp monitor app. Saw I was running at about 135 F when it shut off. Shut down machine for awhile. Next try it was running at 107 F. Again, after about 20 minutes the screen went blank.
• Tried setting it to sleep after 5 minutes. iMac had no issues going to sleep and waking. I left it in sleep mode for an hour and it woke without issue! But after a period of use it went dark again.
• I am NOT able to wake it up with Ctrl-Shift-Eject or Cmd-Option-Eject or any combination of those keys regardless of how hard I hit the keyboard.

I want to try a reinstall, but am worried about it going dark mid-install.

I'm going to try recording the time until it goes dark to look for any patterns. I did not that when I cleared memory, it went less than a minute later. Coincidence? I'll play around some more this weekend.

iMac 24" mid2007

Thanks for calling me a troll.

FIrst off, you didn't ask for ideas, you asked about using an external monitor. That is something only you can test, as I pointed out twice.

If you want to be illogical and turn this into a war of words then you are on your own. No point in wasting time on people who insist on sticking to preconcieved ideas.

Hereby unsubscribed from this thread.

Good luck with your troubleshooting anyway.

Thanks

I found another thread (this issue is far too common) where someone had some success by disabling bluetooth devices.

There are definitely several different problems that manifest into a black screen (logic board, graphics card, led, memory, etc). Bluetooth seems like a stretch, but I've seen stranger. I'll post my results back on here.

HI,

Just a follow up on my issue. I've had the graphics card in the iMac replaced and the issue has gone away. It seems like something in El Capitan triggered an issue in the card. Older OSs were happy to boot and run, but the new one triggered something.

Again, I see people are not addressing the issue of the MAC running hot. Try to set your brightness down to the lowest setting possible

as a test run for a day or few. Also run SMCFancontrol software for your iMac and set the fan to MAX.

My Mac has not went blank since the day I ran SMCFanControl and set my brightness down to 1.

Best of luck to ya.

I tried this without any success. What do you have your fan speeds set at?

I tried letting mine cool (turned off) for several hours. It was running much cooler when I turned it back on, but it still went dark after 21 minutes. It had been running 20-30 degrees cooler from the last time I had used it at the time it shutoff. I don't believe this rules out temp, but I'm not seeing a clear link.

Mine will also go dark when it is already dark. Meaning, it goes into sleep mode and will not wake up. Screen brightness definitely has no impact in my case.