Hello, have you blown the dust out lately? Let it cool for an hour & see if you can get these...
Get Temperature Monitor to see if it's heat related...
And/or iStat Pro...
Please can you add a bit more description to your post about fixing this problem.
Dust? What dust and what are you proposing?
Your links, these take me to third party product home pages with no suggestion or mention of fixing an iMac screen that randomly turn off.
The iMac contineus to randomly turn off, this has only happened since upgrading to the latest version of Lion.
Hello Ashadur: My 27" iMac (Mid-2011), Mt. Lion 10.8.1, just started with this same issue a few days ago (today is 4SEP12). Here are the particulars for others affected.
1- Video suddenly goes black. Computer is still functioning, apps all running; its just like I invoked "sleep", but I didn't and keyboard or mouse will not "wake".
2- A hard restart (using the power button) will bring video back, but sometimes it goes black before machine is completely booted.
3 - Found that reducing screen brightness to 3 or 4 clicks above minimum brightness is, at least, a work-around. With display brightness reduced the panel has never gone black! If I turn up the brighness to normal (about 3 clicks from maximum) the panel will go black ususally withing 45 seconds.
4 - Found another user with this same issue that discovered that the keystroke combination Shift-Control-Eject coupled with some keyboard activity sometimes brings the video back. I've also found this to be true, but it usually blacks out almost immediately again.
5 - My machine is 1 year and 4 months old, with no AppleCare extended warranty. I spoke with AppleCare and the tech was not aware of this issue. He said, that so far, it was not a reported "Engineering Issue". He also said that IF it became an Engineering Issue, that any machine would be repaired by Apple regardless of warranty coverage.
6 - My only recourse is to make an appointment at a Genius Bar (100+ mile trip!!) and have them try to diagnose. Of course, I'll be out the repair costs, which I will not be able to afford since those reporting this same issue on both Apple Discussions and on other Mac Forums have reported that panel/backlighting replacments have solved the issue. That is probably a super-costly repair.
7- So... I'm likely stuck with using this machine until it quits at a much reduced display brightness. This is the first Mac I've purchased without AppleCare and I'm a charter Mac user (Jan 1984!). I let the one-year anniversary slip by and forgot! AppleCare will be in the cart on every purchase from here on out! Live and learn!
I took mine to the genius bar last week. I am confident the genius knew what he was talking about as he pointed out that something was not working properly. Bottom line, recomendation is to back up and reinstall the operating system. I have not done it yet, but plan on doing it this week.
I am in a similar position - my imac is just over 1 year old and I meant to purcchase the extended apple warrantly but it was past the date when I called in so I am stuck with no warranty. I also live over 160 miles from an apple store but I did make the trip last weekend to the genius bar. The fella at the store had never heard of the problem - surprising considering the number of posts on here about it - and he did a system reset and just two days later the screen black-outs have continued. I have no idea what the next step is.
Did the system reinstall work for you DavidNY63??
Any other suggestions out there?
Thanks DavidNY63. Please let us know if the reimage helps. I cannot reimage at this time because I am in the middle of some contract work. But after the jobs are finished I can and will if you find it cured your issue. I have been curious to read that this issue seems to have started with the introduction of Lion (Mac OS 10.7). I never had the issue appear until after installing Mt. Lion (10.8.1). Thank you for keeping us up to date.
Dear lewaseven, et. al.,
I have read several posts (different thread) on this same issue and it was solved with a panel/backlight kit replacement. That is very likely a $900+ repair! So that is not an option for me.
I suppose it is possible that the issue could be a mixture of hardware and software, i.e., updated drivers that are pushing the video card too hard too hard or something like that. But the bottom line is that those of us in the boat with no AppleCare are going to have to either settle with the workaround of running the monitor on a dim setting OR hope that someone finds a software workaround (such as a re-image, or a driver update, etc.).
Thanks for all on the thread for their input. DavidNY63... we will standby to hear the results of your reimage.
Ponca City, OK USA
Some good news, i was talking to an advisor on the phone because my issue has since come back. Since my original post i have not had the problem due to an update but all of a sudden since yesterday the problem came back and with it 2 new problems, my screen starts flickering and also the left side of the screen is dimmer than the right side. Iv spoken to customer service advisor and then transfered to a manager who told me this issue was acknologed in the states (i live in the UK) and they had a re-call for this problem, so if you live in the states phone Apple. For the UK readers who are experincing this problem there wasnt enough volumes of call to show the problem was happening here, thats what the manager told me. So if you have warrenty or Apple care call up quick to get it fixed.
If you guys are still having this issue, check this thread out it might help? (People out of warrenty)
The repair is not an option for me either - way too much money! I can buy a whole new computer for that!!! I have tried running my screen on very low - only on 2 bars - and the screen still went black. What a silly issue. I do hope that some solution exists somewhere that is reasonable, because a $900 repair is certainly NOT reasonable. I am impressed that you are still a proud apple user. I tell you, this situation has really put me off of using apple again in the future. This was my first experience and it has not been the most positive one, that is for sure! Everyone I know swears by apple...that is the reason I gave it a go. I went big, and I feel that I have lost big. Warranty or no warranty, I think there are enough people out there experiencing this same problem that Apple should be doing something about it. What does it take for it to become an "Engineering Issue" so that they will recognize that it is a problem? Just curious if you know...
As for David NYC63, I did not do the re-image. I did the system reinstall and that did nothing to help the issue at all. I am at a loss, and am seriuosly considering buying a PC laptop. I have not had much luck with apple...and it is very expensive!! Maybe one day a solution that works (and is reasonable) will come up.
Thanks everyone for your feedback and suggestions!
I'm sorry for your predicament and first-time experience with Apple products. I can only say this: in over 28 years of using Macs this is my first big "uh oh". Up until my last two purchases (my current 27" iMac and my current MacBook Pro 15") I have religiously purchased the AppleCare extended warranty.
Now to be honest, I have ended up using the Applecare on a majority of my purchases, but for what I considered the normal failures: Optical drives and hard drives. It seemed that close to the end of the third year I'd always have an optical drive go bad or more rarely, a hard drive quit on me. As I said, those are really common failures that any computer will experience. They are both mechanical devices subjected to a lot of wear and tear/usage and so I've not been "surprised" to see them go south. I worked at one time in a very LARGE corporate environment in their computer deployments and we constantly were replacing hard drives and other mechanical parts... on Dells and HPs. So, that I consider just part of owning the equipment.
But this video-goes-dark issue is a genuine exception for me. I blame myself for the predicament since I forgot to purchase my extended warranty. Now, I, like you, feel that since others (we don't know how many) are having this issue that it is more than a random part failure. It seems like an Engineering Issue to me.
I suspect the only way to get this KNOWN to Apple is to start rattling the cages at the Genius bars in the Apple Stores. Unfortunately I'm 100 miles from the nearest Apple Store and can't at this time afford to make the trip. I did call the Apple Store in Tulsa, OK (my closest) and the manager was not aware of this technical issue. I as not allowed to speak to a "Genius" or any repair personnel. I also called Apple's Applecare number, but since I have not purchased AppleCare I was deadended there as well. They could only recommend I take the machine to an Apple Store for diagnosis.
As for Apple services in the past, I've been more than pleased. If you are under warranty your issue gets resolved... period! And since I'm so far from an Apple Store, the AppleCare service actually sends a technician to my home/business!
So, the bottom line is that you and I are probably stuck with a design flaw that again probably won't get classifed as an Engineering issue.
All I can say is, "I will buy AppleCare from now on." It's good protection for gerneral very good devices and it gives you leverage with the Company when you do happen to get a lemon.
Ponca City, OK
It's starting to sound like a broken record, but I am having the same problem. I have the iMac 27" and I bought it last July so I am just out of warranty. My screen goes black just like you are describing. I then ran a hardware test on it and it told me there was a problem with the hard drive which immediatly went out on me and I had to take it into an Apple service provider. They replaced the hard drive which was recalled by Apple. They claim mine is not part of the recall even though it is the same manufacturer and bought in the same time frame as the recalled drives. THey never could duplicate the screen issue. I though that maybe replacing the hard drive would take care of the screen issue, but two days after getting it home, I have the same screen issue.
I have always had a Mac and grew up on a Mac since they first came out in '84. I have an old Mac G4 that is close to ten years old and it still runs fine. So you can sense my dissapointment in Apple that when I finally upgraded my computer I got a little over 1 year out of it and now all these problems. My brother is a long time Apple user and he has noticed a decline in reliability with their software programs. I hope that Apple isn't becoming another Microsoft - put out the products and let the customers find the problems for them.
I will be contacting Apple tomorrow to report this issue. I feel that there are too many of us having this problem. It's an engineering issue that should be fixed by Apple whether it's in warranty or not. Even a PC lasts longer than a year.
Hello Charles: Thank you for your post. I would love for someone to push this issue with Apple and perhaps convince them of the truth, that being, it IS an engineering issue. There are many affected. Because of my physical location (100 miles from the nearest Apple Store) I cannot perform that role. I don't have the time or the $ for gasoline to make that push right now.
My 27" is still experiencing the video blackout issue if I run the brightness any higher than about 5 'clicks' above minimum. This is still adequate for dim room lighting but not for full daylight. Usually, when the video blacks out, I can get it to come back after a few command-option-eject keystroke combinations. It usually takes several. Sometimes the video goes out again almost immediately, but after trying and trying I can usually get it back long enough to restart the machine.
I am also wondering if the issue is heat related. I don't have enough good emperical data on this but it "seems" to be more touchy when the ambient temps are highter and the processor is getting a workout (more heat being generated inside the machine).
Sadly, without AppleCare warranty there is no good recourse to approach Apple with such an issue. I too am a charter Mac user. This was the first machine purchased without AppleCare (I let it slip and forgot). But that won't happen again! :>)
I would appreciate hearing from others on this thread if they have gotten anything resolved with Apple on this issue.