Mid 2011 iMac Graphics Problems with Yosemite

OK... I have said this 4-5 times! The software either overheated, or caused the Radeon cards to head south, and it might be the case that the Radeon cards are failing on their own due to some internal conflict with something in the Yosemite codes. In any case, you have a mid-2011, so heres the deal - the Radeon cards are warranted for FOUR (4) years (that = mid 2015!!).. If you call 800 my-apple, ask for a senior tech, and tell them that you think your card has died, (1) the tech might have some way to lead you to a boot, and then will probably want to run you through some diagnostics. Thats what my tech did. He finally agreed that the software had somehow compromised the graphics card, and issued the CS Code, which was, in fact, an 'add-on' extension of my applecare warranty, which covers 100% of all repairs. I got my AMD Radeon HD 6770M 512 MB card replaced, as well as the internal superdrive replaced, (the drive would not accept the Apple install dick..kept spitting it out without reading it, so luckily I had a $30 Samsung external ddvd/cd drive that worked!) for gratis! So, ignore all of the seemingly well intentioned fixes you see and hear about, get ahold of apple, and ask where and when can you get your Radeon card replaced, and would they give you a CS Code to take to the apple store so that the charge will be to apple, and not you.

OR, wipe, reinstall, disable transparency, reset partitions, reset PRAM, and on and on. I followed all of those tricks before realizing that NO temp fix would keep me going, and that I needed to get 'er done right!

Good Luck!

Make an appointment with the nearest Genius bar and have Apple look at it. If it's the card and you're within the 4 year window they will replace it. free.

Agree on this.

I just get my iMac repaired back from Apple. Although it takes quite longer (2 weeks), now I don't have the display or crash issues so far.

I have exactly the same problems (iMac mid 2011/Radeon 6770) but Apple Support say they have never heard of the problem, refuse to look at these discussion boards and are being particularly unhelpful.

deltone ... thank you so much for your post.

And all who have helped me identify this issue.

I did ring Apple, they said they would honour the replacement of my AMD Radeon HD 6970M 2048 MB.

They found an Apple preferred store for me, said I did not need a CS code, as it was a known issue.

Took my iMac in on Friday and picked it up with a new Radeon card installed, yesterday (Wednesday).

Easy, but still a pain. Glad I have got it back though.

A few notes:

• I had to re-install the OS, as I think with the amount of rebooting I had done previously messed it up. It would only boot in Safe mode.
• After any install / re-install, best to check and repair Permissions in Disk Utility
• On my invoice (zero to pay incidentally) there was just a 3 month warranty on the Card, which surprised me.

All good now.🙂.. thanks again for your help. What would we do without these forums !?

My Spec:

iMac (27-inch, Mid 2011), 3.4 GHz Intel Core i7, 24 GB 1333 MHz DDR3, AMD Radeon HD 6970M 2048 MB, OS X Yosemite 10.10.1

Sorry meant for facemac

Just point them to this link.

iMac (27-inch): AMD Radeon 6970M Video Card Replacement Program - Apple Support

It is on their Web site !

Thanks but my card is 6770!!. Exactly the same problem though.

So i had a very similar problem with my mid 2011 27” iMac. I called apple support and they spent about 1 hour with me deleting all the malware - MacTuneup, Citrix, and Mackeeper. Then I reinstalled Yosemite and the problem is gone.

There is a problem with the NVIDIA graphics cards on these models. I'm experiencing the same problem with my 27" iMac. At first, the machine passed the VST, but today it failed. It also failed the NVIDIA test. Apple will replace the card at NVIDIA's expense.

Just a quick and maybe interesting update for those that have NOT a hardware issue (specifically those with ATI Radeon 6770). There is some issues in Yosemite still that also affected VMware Fusion (very slow virtual machines). Today I installed the update to version 7.1.0 and found an interesting comment and work-around in their release notes at https://www.vmware.com/support/fusion/doc/fusion-71-release-notes.html - specifically:

Some users running Fusion on a Mid-2011 iMac with OS X 10.10 installed may see poor performance of their virtual machines.

Workaround: Until this issue is resolved, the following work around can help:

• On the iMac, run the Terminal application.
• Type the following and press return: sudo nvram boot-args="debug=0x10"
• Enter your password (you must be an administrator on the machine).
• Reboot the iMac.

These boot arguments "make ddb the default debugger" and even though additional seems quite unlikely to make your virtual machines go faster, it effectively does. There is a few comments about this at https://communities.vmware.com/message/2443765 suggesting that "But it appears to be that the problem is with Yosemite running on specific hardware (iMac 12,1 and 12,2). It's not really a Fusion problem at all...it's the fact that there is an interrupt storm going on on CPU 0 (where Fusion happens to live). Even if Fusion is not running on your machine (prior to setting the nvram boot-args flag, you could see the problem by running 'sudo powermetrics -s interrupts"...indicating CPU 0 is having real problems). It's not exactly a hardware problem either... it's something about the way Yosemite interacts with these specific model iMacs. Anyway, the solution will have to come from Apple in the form of a real patch.".

Setting the above seems to take that "interrupt storm" down to acceptable levels... I have done so now and at for VMware Fusion I am back to a working solution. I'll switch Transparency ON again to see if this will bring some change there as well.

mine was 6770 also, and since the card is warrantied for FOUR (4) years, it was replaced.

we got it deltone .... really ....

I'm glad you're satisfied. I was responding to facemac. I think a lot of people coming to the forum to seek help might not know that the Radeon cards are warranted for 4 yours.

AND, BTW. . . now I see that nvidia cards are being mentioned?! That software seems to do some damage to video cards!

On Thursday I took my two months old MacBook Pro 13" retina into the Apple Store for a display replacement due an accident. Long story short my MacBook was in my backpack and I ran over it with my truck. The screen did not brake but got damage. Even that accidental damage is NOT covered by Apple warranty the Genius Bar girl was kind enough to replace the display for free under warranty. Then I asked her about my mid 2011 iMac and the problem I have after installing Yosemite then she told me to bring the iMac to the store when I come to get my MacBook back. I did that today in the morning, they ran the test and the GPU was totally fine. Then I turned ON transparency and they ran the test again and the GPU failed the test. I asked them to replace the card and they say yes but I need to pay $150 + labor. Then she check with the store manager and even over the phone with their supervisor and they said that it's NOT true that ATI Radeon cards are warranted for 4 years. All the parts and components inside any Apple product (computers, phones, ipads, etc) are covered by Apple warranty and not by the component manufacture. Don't get me wrong here, please, I'm not telling that deltone is lying, my point here is that the same way I got a free display replacement for my MacBook Pro, some others got a free GPU in their iMacs but that's not the rule for everyone. Those that got their GPU replaced is because they are still covered by Apple Care or they were atended by a Genius Bar clerk that was kind enough to replace the GPU for free, not because they are covered by ATI warranty.