Q: Red and green square dots?

Could be the anomaly is not caused by system RAM, if this

pertains to Dark Pixel, Bright Pixel, or Foreign Material...

•Learn about About LCD display pixel anomalies for Apple products released in 2010 and later

However there likely would be a fee to determine what may be

an actual cause, be it a graphic processor issue, or other.

This conversation supposedly branched to another thread,

but I hadn't found the linked topic yet.

Good luck & happy computing!

I have Apple installed Ram that was installed in my iMac and shipped from the factory (Apple). Just to see if the symptoms are lessened by adjusting the video card resolution, maybe somebody here could try it and report. Thanks

jmf

I posted previously on another thread, but I'm another person experiencing the same issues.

2011 iMac 27-inch with the Radeon HD 6770M running 10.6.8 (Snow Leopard); At first I was just experiencing flashing squares every now and then but they worsened over time, gradually taking over my entire screen. I've recieved video card related errors while playing a game on my Windows partition (I run Windows 7 through Bootcamp) that caused the game to freeze to crash, and it has gotten hung up and crashed at least once on both my Mac OS and Windows.

I've been trying to keep up with the forum posts to see if any clear solutions have been posted, but I don't see any? Unless I missed it. I ended up taking the computer into the Apple Store last week, only to be told it was the OS and that it needed to be reinstallled. Note that they said they could not replicate my problem "running their software" prior to the fresh install. They did not completely wipe my hard drive as they left the Windows partition in tact. I asked them to turn it on in the store to make sure that it had actually fixed the problem, and guess what! It worked perfectly in the store.

Of course.

Took it home, worked fine for a few hours... I decide to try installing some of my backed up files. As SOON as I bring up Time Machine, I begin to see squares again. Joy. I haven't installed anything but the drivers for my mouse and keyboard (I use a razer naga and anansi) and the only thing I plugged in was my external hard drive.

I was considering upgrading to Maverick but I've heard that it might make the problem worse? Has anyone had success with anything? I want to take it back to the Apple store, but I'm afraid they will just wipe the hard drive again or start throwing random parts at it. Has anyone had success with a replaced video card or any other parts?

not a software problem. No one is seeing Apple scramble to write special code for these aging iMacs. They're swapping hardware out, and in some cases they're replacing entire machines. They are lemons. Why, I think relates to the generation of hardware, its compatability, cabling, sensitivity to heat and dust. The OS version doesn't matter.

Take it to the Genius Bar. Pay to get it fixed. Once they repair it, look very closely for the issue to reappear. Stay at the Genius Bar and watch it. If it's fixed, congrats, if not, chances are they'll replace your iMac or credit you toward a new purchase. Either way, it's pinned on Apple to correct the problem 100%. Don't try it on your own, because you might replace an entire machine to isolate the issue. Apple hasn't figured it out, what makes us think we can?

Agree with Soulnation that this does not seem to be something that we can troubleshoot.  Still not convinced if it's a software or hardware issue but that's beside the point.  It seems as though the best success has been a fresh re-install of everything.  However multiple people have been finding a temporary fix only. 

The only thing that ended up being successful was documenting the issue in detail and showing the Genius Bar.  Was offered a significant discount on a new one and still have my old machine that I can use for a second monitor or may sell to cover more of the cost. Just not worth the time to continue troubleshooting this issue IMO.

If you take it to the apple store for repair, make sure you spend time testing it in their store afterwards. I've found just scrolling back and forth in finder quickly works well to reproduce the issue.

I understand that there is a recall for 27" iMacs from 2011. This hasn't helped me as my iMac is mid 2010.

The affected iMacs contain serial numbers with the last four characters of DHJQ, DHJW, DL8Q, DNGH, DNJ9, DMW8, DPM1, DPM2, DPNV, DNY0, DRVP, DY6F, or F610. The errors have been previously noted on both the MacRumors forums <http://forums.macrumors.com/showthread.php?t=1225604>  and the Apple Support forums <https://discussions.apple.com/thread/3255699?start=0&tstart=0> .

I've already posted a few times in this thread, but I'll mention mine is also a mid-2010 and my video glitches do not look anything like the screenshots in either of those 2 forum links.

Also, I have never changed out my factory-installed RAM so I don't thnk 3rd party RAM is the issue as some are guessing.

:-/

I am just writing to also comment that I am still on original factory ram, not third party.  Seems that we are also running the same machine and the squares that I see are different than the two recent links. 

My video issues are different than the links that susanmargaret posted, too.

My issues are driving me crazy, because the machine is freezing up in the Finder so frequently - also when changing users.

So, I took the plunge to take my mid-2010 27" iMac to the Genius Bar - even though AppleCare is expired.

They, of course, insisted that the video card (~ $250) is bad. I'm going to bet that the video card replacement won't fix the issue, and I'm hoping that Apple will take responsibility somehow.

I'll report back the outcome of my "plunge".

steinmanal wrote:

 

They, of course, insisted that the video card (~ $250) is bad. I'm going to bet that the video card replacement won't fix the issue, and I'm hoping that Apple will take responsibility somehow.

 

I'll report back the outcome of my "plunge".

yeah, this is really the big question about how Apple is approaching the cost to repair to a "t". With a pentalobe-protected MBA, they give you 1 price to fix everything. With these iMacs, my thinking is they're doing diags and then tailoring charges accordingly. I think they reserve the right to keep replacing stuff and charging multiple times. If this scenario holds true, it's why I'll never buy an iMac again.

EDIT: I'll also add that I'm getitng varying freeze/glitch finder issues away from the pixel norm issue, and I think it's a Mavericks interaction with the junk hardware in these boxes. For example, you roll back to 10.6.8, chances are the iMac lights up like a Christmas tree instead of diplaying an etch-a-sketch melee.

The tech at Apple assured me that, if the video card doesn't fix the issue, then 100% of the cost of the video card would go toward whatever the next repair might be. It's not super re-assuring, since they could replace a bunch of increasingingly expensive hardware - and then issue could persist.

hahaha, awesome, way to go, Apple. 21st Century shanti auto-repair in effect right here.

"We think it's your transimission, but if it ain't, we'll say, 'aw shucks' and replace the engine next."

Thanks for putting us in the loop steinmanal. I hope they the Genius Bar knows something we don't.

jmf

steinmanal wrote:

The tech at Apple assured me that, if the video card doesn't fix the issue, then 100% of the cost of the video card would go toward whatever the next repair might be. It's not super re-assuring, since they could replace a bunch of increasingingly expensive hardware - and then issue could persist.

Yea it's definitely the video card.  Called several fruits bars And apple repair centers and they all said the same thing.  Apple knows about it they aren't coming up to the plate.  Does anyone have corporate contact info because that's my next step I'm going to take.