OSX Lion + 2011 iMac 27'' + Video = Freeze

Hey all, I just picked up my machine from the apple store. I had the graphics card replaced and i'm running 10.8.4. As of 20mins now everything is running stable. I'm still testing the machine and trying to replicate the artifacts. A sure fire way was using preview and having the dock magnifaction turned on, however these are working fine now. If there are any tests that are known to make your machines artifact I would like to try them on mine to see if this is an actual fix. Let me know and I will keep you guys updated.

First of all, I don't think it is ethical to be censored for mentioning "local authorities" and I don't think authorities will like this too.

Also, for sake of clarity let me express that I didn't wrote "I encourage you to report this" (that would be useless). I said report this to Tim Cook (I'm not publishing his email this time) because that has been the only way they have replied me, all other ways I tried have proved to be useless including this enormous thread. If this thread is not relevant then what could be.

Andrew

I also have a 27" mid 2010 with a 1GB ATI Radeon HD5750 graphics card. The mac is left running 24 hours a day and whilst I do not want to talk it up, I have not had the issues other users are facing.

I have additional third party ram installed and am running with 12GB total. My Mac has a SSD and hard drive which were factory installed.

So it would seem to me that the issues are not affecting all mid-2010 units.

I must say that I personally love the Mac and would not return to a windows machine out of choice, however, given the fact that these machines are expensive Apple should really get their act together and sort it out as their customers are becoming increasingly frustrated to the point where they are probably losing customers.

All,

In case this helps anyone out there.

System: iMac 27 mid 2011 3.4Ghz HD 6970M 2GB, 20 GB (4 original + 2 8gb Crucial)

Issue was the screen would turn white or psychodelic

I finally got fed up and replaced the video card with a cheaper one the 6770M 512MB $210

opened the computer (first time) removed the logic board and replaced the video card

It has been working perfectly! no more issues. Done!

Next I will order some thermo paste to see if it will fix the expensive video card.

but not for a while.

I dont run videos. This has started happeneing within the last few weeks. I've had my imac since 2010. I updated to Lion months ago. I'll be working in Photoshop or have it open and my mac freezes but the curser moves. No I cant click on anything at all. I have to restart my computer which ***** since most of the time I have several images opened in PS that Im working on and have to start all over again. Anyone find a solution yet?

After doing my best to submit proper bug reports and going back and forth with Apple engineering for a long, long time, a month ago I got a phone call from Apple support telling me they wanted to resolve my issue and would replace my video card even though it was out of warranty. A day later I was booked into the local Apple store. Five days later I got the Mac back. They replaced the video card (with another HD5750) and the logic board, although given the results of Anthony and Entwiner above I'm pretty sure simply replacing the video card would have done the trick. Anyway, I haven't had a single problem since I got the machine back and am now running 10.8.4 without issue.

Naturally I'm thrilled Apple fixed my machine (mine also suffered from a dodgy hard drive, which was replaced a while ago under recall, so all that remains of the machine I bought is the optical drive and display). The only theory I can come up with is that 10.7 and subsequent system updates put increasing levels of 'stress' on the GPU, revealing a hardware fault that was probably latent in my particular ATI card. Perhaps there was a batch of cards with the problem; perhaps it only affected a few others. The card I have now is exactly the same model and it works fine (as it does for Fireblade69 above).

If Apple hadn't come to my rescue I probably would have attempted to replace the GPU myself, although opening up an iMac is a pretty terrifying ordeal. Taking it to an Apple store and having them replace the card would be a much better idea.

Do you think there is any chance Apple will issue another late recall?

I was due to get the HDD replaced on my late 2010 27" iMac even though I had already replaced it, but then they reneged on the deal because the contractor would have to return the original HDD to Apple (to get paid) which I had thrown out a year earlier.

I have the ATI Radeon HD 4851 GPU, and the only way I can run is by removing the ATIRadeonX2000.kext file and having fancontrol on a pretty high setting. I can't watch some videos, my iSight doesn't work in Skype, my time machine is flakey, but I can still do most of what I need to do without Quartz Extreme features. Anything to do with graphics I run on my Windows 7 VM and its just fine, but still a pain.

I would replace the GPU myself if I could figure out where to buy one, how to deal with firmware issues, etc.

Did Apple ever actually admit there was a problem with particular ATI cards?

Looks like Apple will now replace the AMD Radeon HD 6970 cards in Mid 2011 27" iMacs

http://support.apple.com/kb/TS5167

Doesn't really help all of us with AMD/ATI Radeon HD 4850 cards in late 2009 27" imacs, does it....

great news for most... but my 27" 2.93, i7 with the ATI Radeon HD 5750 does the same thing and has for over a year now.

The only way i can work is to keep apps running all the time with a constant stream of some kind (audio or vid loop) to keep the machine "hot". It only blacks out when its cold or after a restart. It can take up to 45 minutes of holding shift+control then eject, wait a second, then hit the space bar to get the display back until it "heats up" again.

Annoying as ****.

What now Apple?

but it helps to imac 27's owners like me. service center in russia replace graphics for free and problem completely solved. enjoy, call to apple, jusk ask about your problem.

I have the same problem with my 2010 iMac with an ATI Radeon HD 5750. I can get it to not crash if I run in safe mode. If I'm not in safe mode, if I manage to get starcraft running before it crashes it works okay ... very odd workaround. It has been having these problems for more than 2 years but I forgot to buy applecare and have figured I'm out of luck.

Apple should extend this program to 2010 iMacs with the ATI Radeon HD 5750.

Update: The machine (2010 27" 2.93, i7 with the ATI Radeon HD 5750) was acting really squirrley last week so i ran the usual HD tools and checks. Turns out the HD went bad and smart status failed and couldn't be reformatted. I only had about a week left on the warranty so i called Apple to setup repair for everything. They replaced the video card, HD and optical drive (humming).

I picked it up today, started to reinstall apps etc. Things were fine for about 4 hrs then the screen blacked out again!

Apple agreed to continue the repair so back it goes. This time it seems they will replace the backlight since the machine never goes off, the screen just dims. The tech i spoke with was very knowledgable and had me try other things that we hadn't gone over in the past. Since I can see the finder and windows with a flashlight against the glass to click etc, he felt it was not an issue with the new card, however the old one left artifacts all the time.

We also have a 2009 21.5 imac doing the same thing (out of warranty). I may get the backlight fixed since its much cheaper ($125+) than the card which seems not to be necessary.

Apple support and customer service has been stellar, they're really on top of things. I'm confident it will be resolved this week.

I really hope everyone on this thread has a positive resolution to thier issues, it's been a real pain here!

Another update: Apple replaced the backlight, I picked it up this am and its been running perfectly so far. I will update as necessary.

This machine never turned off, only went black (or very, very dim) but you was still running just fine. Hopefully the backlight will resolve it and may help others with the same issue. It is a much cheaper repair than the vid card.

it's helped for my mid-2011 i7 27" iMac 🙂

for free 🙂

Hi everyone,

I have a mid-2011 iMac i7 3.4 with the 6970 card on OS X Lion v10.7.5, and was experiencing freezes left and right -- the computer would lock up and become unresponsive, but I could still move the cursor around. This would mostly happen after the computer had already been asleep once, and I was editing RAW photographs, but it could happen within 10 minutes of a reboot, too. It would happen every day, and the only cure was a reboot.

After finding this thread, I resigned myself to packing the thing up and taking it back to Apple to get the 6970 replaced, but what made the whole thing stange was that this never happened before Apple upgraded the video drivers back in 10.7.3. I found it so strange that this was a hardware error -- it worked perfectly before that!

Well, when Mavericks came out last week, I figured what did I have to lose? I backed up my files and upgraded the machine from 10.7.5 to 10.9, and guess what? The computer hasn't locked up since! It use to crash every single day. Now, nothing!

I've tried everything: editing tons of RAW images, putting the computer to sleep again and again, and playing videos, but the thing has worked smooth as butter -- it's astounding.

Will this fix everyone's problems? I have no idea. I'm perpetually in fear that the freeze will happen again, and that I've just been lucky. That said, my suggestion:

If you can, try upgrading to Mavericks and see if this solves your problem. Before doing so, please please please back up your files. Test your iMac for a week, and report back. Maybe this was a software issue after all?

tl;dr: upgraded to Mavericks, freezing gone