Q: Red and green square dots?

I've tried every OS upgrade path that allows you to jump to Mavericks at the app store, currently using 10.9.1.

Originally, I had really bad symptoms during the time of Mavericks release and was hoping it would fix my iMac. It was the same after the upgrade, totally frustrated I was ready to pawn it for parts....

What I did was erased my hard drive, clean installed 10.6 and then upgraded. Before I downloaded my first upgrade jump, I noticed hard pixel distortion and really bad symptoms in 10.6. So I figured I had hardware issues. Ran the diag tool and everything was fine. (scratching my head at that point, and reading this novel of a thread)

Opened the iMac, removed the LCD and went to town with a filtered compressor & air nozzle. 30 minutes later I reassembled and the difference was "whoa".

Continued the jump to 10.9.1 and then isolated serious issues running Safari and my energy saving modes. Nixed those. Here I am now running failry smooth, hoping to keep this going for a few more months. Probably will dissasemble again and de-dust...

moral of the story: what I do externally to this machine makes a bigger impact than anything Apple has offered up in their upgrade suites. Sounds like it's a hardware issue---for me anyway. Would be awesome if I was wrong; that would save me $1K or more...

The last thing I'll add is that my iMac's symptoms gradually became worse over time. This was a buildup of glitches to a point where I couldn't take it any longer. I didn't have Apple Care, so I tolerated the increasing pixel junk.

I kinda attribute this to a buildup of dust over time. Some circuitry has probably overheated over the past 4 years and it's past the point of normal function. Luckily, I can isolate the offending apps and modes that trigger this machine's disease & relapse.

Maybe Apple's reading this and wants to offer me a job in their hardware design department.

www.jared-french.com

CHEERS.

Add me to the list, Mid 2010 27" 2.93 i7 iMac. Clean install of Mavericks didn't help, symptoms showed up immediately.

On "cold" starts it would get pretty bad and even freeze up so I would have to force it to shut off and restart. I would process a video in handbrake to get it to warm up and after 10 minutes or so it would go away.

I was given a 27" LED Cinema Display so I connected it to see if it would help. It's been 3 days and I've seen 6 squares and everything seems stable now.

Hello Everyone,

Sorry to say it, but I am glad that there are many others in the same boat.  Until I came across this thread I thought it was just my iMac with this issue.  I wanted to add my experiences so far of troubleshooting and things that I have noticed along the way so that maybe we can get this thing sorted out somehow.  I apologize for the long post but want to pass along as much info as I can think of to help out.

My AppleCare covered me until 9/28/2013 on my 27” iMac and I started to see a different graphics issue just before I started having the same multi-colored square dots. 

I noticed my first issue in both World of Warcraft and Minecraft.  In WOW I had an issue that was similar to Frudahs’ pictures (folders with the squares showing up flat along the folder graphic) but was instead related to names of characters in the game.  The in game display showed character names but would actually spin around, go backwards and generally had a very bizarre behavior (attached a picture of this issue).  My characters “skin” would also fade out/flash and turn black/white.  With Minecraft I saw an odd behavior of similar surfaces flashing rapidly (turning white/green/black, etc) and not displaying the skin/texture.  The screen would flash green uncontrollably and would be completely unplayable.  I thought this was the graphics card starting to fail so I took the iMac in for the video card replacement.  The care plan expired about a week before but the store was nice enough to replace the video card so I thought I got lucky.  I do not recall if started seeing the squares before or just shortly after the graphics card replacement but it was around the same time.

Since the graphics card was replaced, Apple still “covers” the graphics card for 90 days I was able to take it back and have the techs work on trying to fix the squares but so far nothing has helped.  The guy at the Genius Bar did observe the squares at the store when I was there.  At that point he said they would swap out another graphics card and a new mother board.  However after over a week of having the iMac the techs said that they could not replicate the problem even when pegging out the memory with running several applications.  I don't believe the issue was thoroughly examined since I ran into the same problems the very next day after returning home.

Apples computer diagnostics showed that everything was fine (both for me and for the techs).  When my computer crashed a couple of times I kept a copy of the report.  The tech claimed there was a issue with the kernel and that it related to my Logitech wireless keyboard.  I stopped by, dropped off the keyboard and wireless connecter for them.  They tested the computer for 24 hours and said that they did not observe the squares.

The tech manager said told me that they did not replace the video card or motherboard (even though they had it for a week before even talking to me).  He said that he didn’t want to throw parts at an old machine if they could not replicate the issue.  He also said that since they are not seeing the issue, that it must be my setup somehow at home and that I need to troubleshoot wireless devices and/or change out the RAM.  I will likely try to take it back in again to see if I can get any additional help before they make me pay for everything.

Observations:

1. The quantity of squares and if they flash or are still seems to mostly be related to running more   applications / using up more memory.
2. The squares are not seen when logged into a game, watching a DVD or change a program to full screen.
3. If I let the iMac simply load and sit for a while w/o opening applications I sometimes still see the squares.
4. I have not been using Safari, mostly Firefox and notice squares more often when I open several tabs in   Firefox (once again using up more memory).
5. If I jump to a second desktop, the squares disappear temporarily but will start flashing again.
6. If the squares are not flashing, I can drag the mouse over GUIs and see that the behavior of the squares changes when I scroll over buttons, scroll bar, etc.

Troubleshooting:

1. Used a different power cable (one from Apple Store) and had the same result.
2. Moved the power plug to a different outlet and replaced the surge protector.
3. Removed everything that was plugged into USB.
4. Removed sound system that was plugged into audio port.
5. Removed ethernet.
6. Used only the Apple Keyboard instead of my old Logitech.
7. Turned off wireless.

Squares Most Frequent While Using:

iTunes, iPhoto, Chrome, After playing a game in Steam and when using AppleScript.

Conclusions/Insights:

1. In my experience, replacing the graphics card did not work.
2. I have not purchased new RAM to see if that helps but I do not believe it will help with this issue.
3. I am still very curious about the motherboard and/or connections to the board as that appears to have      helped out other users.
4. Based on responses in this thread and what I have seen, this is likely related to software / OS.  Maybe a compatibility issue?
5. Also since so many people have spoken up around the same time it seems more likely to me that it is     software related (but is only a guess).
6. If this is related to a bad Kernal response, I really have no insight to fixing/troubleshooting such a thing.
7. Typically see fewer squares with different colored backgrounds (probably just because the squares blend in but who knows) and probably the worst with a darker background.
8. Have also observed pretty much a seizure from the machine where everything on the screen    flashes/flickers and when it happens I cannot force quit anything.
9. Makes me wonder how many more people have not spoken up about this issue and how many more need to before we get some actual help for a fix?

Specs:

OSX v 10.9.1

Processor 2.93 GHz Intel i7

8 GB 1333 MHZ DDRS RAM (status ok on all)

Graphics: ATI Radeon HD 5750

ROM Revision 113-B9710C-238

EFI Driver Version 01.00.417

Resolution 2560x1440

Plan To Do The Following:

1. Remove / Re-install Chrome
2. Troubleshoot additional apps
3. See if I also observe no issues in Windows 8
4. Reinstall iTunes
5. Take back to Apple Store again
6. Maybe purchase new RAM (but unlikely unless if I have more proof that it will help)
7. Bang my head against the wall more??

Previous graphics issue (just before seeing the squares).  Notice the names and quest text.  I still believe the issue shown below relates to the flashing squares but do not know for sure.

Is there anyone here with the square symptoms that never upgraded to Mavericks? I recall first noticing this issue within a week or so of upgrading from 10.8 to 10.9. I also have a 2010 MacBook Pro and a 2012 MacBook Pro Retina both upgraded to Mavericks with no sign of this issue.

I'm starting to think the Mavericks upgrade changed the driver or video BIOS specific to the 2010-2011 era iMac video cards. Perhaps when people later downgraded back to 10.8 or older, the OSX version was downgraded but the hardware wouldn't allow a downgrade of the driver or BIOS. That could be why they issue persists.

I get a lot more squares that start flashing like crazy whenever I'm watching any sort of web video, or on web pages that have a lot of animation or banner advertisements. I also notice the flashing increase when there is a lot of hard disk activity. I've never had the iMac freeze like some people are saying.

I don't think heat/dust is the issue.

Seadub, mine was exhibiting this symptom while running Mountain Lion.

I have issues with my screen too, I first noticed it right after I installed Mavericks. I don't know if we are talking about the same thing though. I have constantly moving colorful diagonal dashes in case of colors with near white brightness.

I'm quite glad that many others seem to have the same (or at least similar) thing, so it's presumably a SW issue after all.

The transition regarding which color is clean and which one is noisy, is immediate. For example rgb(253, 219, 219) is essentially clean, but rgb(254, 219, 219) is total junk. So only 1 unit of color change counts. This also hints that it's a SW issue.

First series aluminum iMac, 2007.

it's easy to point to software when glitches remain contigious to a finder window, a certain software feature, etc.. But there's much greater propensity for these issue to extenuate from hardware and thus affect the software in bizzare ways. Apple is changing out hardware every instance according to others taking their machines into the Genius Bar.

Not a recall issue yet...sounds like heat, dust and possibly a bad run of hardware Apple lined up in their supply chain. I'll eat my words if this is software related. That said, Apple will eat the cost of my upcoming repair if they can solve this through creative coding....my money says they won't and hardware is the resolution here.

I have 2 primary reasons for thinking this is a software issue:

1. There are people in this thread who had the graphics card and/or logic board replaced and the problem returned.

2. The problem never happens when the iMac is being used as a secondary display or when remoting from iMac to another machine.

that's interesting...but why aren't people showing the TDM/remote vs iMac at the Genius Bar? And that still could be a corrupted hardware path as illogical as it sounds.

Those that had their iMac's repaired by Apple Service only for the issue to comeback are covered; it's pinned on Apple to fix it. It's on Apple to get it right. You go your own road & replace your own video card/logic board it'll cost more and no guarantees on success. I'm holding out to schedule my repair. But not holding out for a recall. I think it's hardware. Apple engineers and programmers still no answer, hmmm. Hardware.

Dedust your iMac, avoid Safari, turn off power save/sleep modes, save your files religously, and expect the worst everyday until you plunk down for a new machine.

I have my iMac in at the apple store for repair (as i've mentioned before). When i brought it in, they told me they would replace the video card and logic board. They called me an told me it was ready to be picked up. They only replaced the video card. I asked to test it out before i took it home. I opened finder and scrolled up and down a few times and the screen filled with pink squares. They said they would look at it again. They called me the next day (today) to tell me it was ready to pick up, they replaced the logic board and ran tests and everything was okay. I asked them to open the finder and scroll a few times. They called me back and said the problem persists. So, they're going to continue working on it.

I'm back again, to comment on the red and green squares issue, after two weeks with a dead iMac. My machine is an October 2010 27" iMac (2.8 GHz i5 with 4 GB RAM) running 10.8.5 Mountain Lion. I had commented on the red and green squares topic here in early December, which I was experiencing with increased frequency and severity. The squares originally appeared only on the desktop, but they were starting to show up in application windows too. I run only Chrome, for what it's worth. It was getting bad enough that I was seriously considering junking this thing and building a PC. The nearest Apple Store is almost 3 hours away, so taking it there for "service" was not realistic.

Then it happened. On New Years Eve day the machine refused to wake up. It tried to boot, but it could not boot from the system partition, from the installation CD, or from a bootable external drive. I took it to an authorized Apple service shop and they determined the hard drive had failed, and it actually prevented the other bootable devices from booting the machine, even though the operating system could see them. Anyway, they replaced the hard drive and that fixed the booting problem. I should have mentioned that this was the second hard drive replacement this machine had, as it happened in November 2012 and was part of the Apple HD recall. This time, unfortunately, I had to pay for it.

While they had the machine taken apart I had them do a thorough cleaning of the dust that had accumulated inside. I knew that it might be building up, as I had pulled the RAM while I was troubleshooting it myself and noticed an accumulation of dust and lint. I restored the machine from my EXTERNAL Time Machine drive. Thank goodness my Time Machine backup was on a different drive, unlike many people do, because my original drive was no longer bootable and data could not be recovered by other machines.

The good news is that I could restore everything from my Time Machine backup AND the red and green squares are GONE. Of course, this is only Day Three of my testing, but I'm cautiously optimistic.

Needless to say, I am extremely disappointed that a $2000 machine that is only 3.5 years old can be such a lemon. I paid much of that money for the superb display; I certainly would have bought something else had I known about the red and green squares issue. I am seriously considering switching back to the Windows world, where at least the hardware is standardized and throwing away a motherboard is only $200 instead of $700+. I will let you folks know if (or should I say "when") my problem returns. In the meantime, thanks to all of you for your debugging efforts. Good luck!

I'm a little bummed on the resale value of these iMacs, thought mine would be higher as I considered switching to a MBA + TB Display. So yeah, $2K for a machine not worth it 4 years later is bunk I totally resound this complaint.

That said, all computers start to become obsolete or unrepairable around 5+ years out. (a lesson in buying the topline options I didn't learn until recently). The 27" viewing experience is really nice, so, given the general life of these iMacs--which most of here could argue is right after Apple Care expires--I'm looking at 11" MBA or Mac Minis +TB Display and never single enclosed iMac unit again.

Retina 27" TB will be nice, maybe a little unecessary, but so is my iMac. Not sure I've ever needed a full 2.93 i7 core and 16bg Ram. Apple sold me well on this, and I thought I'd be doing more intensive work with it..and I thought it would have a higher resale value. My own fault I spent $2K. The takaway with mabcooks is they usually break or get destroyed with coffee & liquids before their graphics cards & logic boards have a chance to croak from old age, heat, dust or that random nearfield EMF that invisibly fries your atomic-level rare earth metals applied to Apple's circuitry.

Isn't this a recall issue if so many of us own the same iMac started experiencing the same issue around the same time?

Do we have any recourse, since our iMacs are no longer under Apple Care?

Could we somehow organize ourselves and contact someone at Apple?

I'm not looking to switch from Apple to Windows. I'm also not looking to replace an iMac that should have plenty of life left in it.

Apple should take responsibility to determine the cause and resolve the issue, even if the machines are no longer technically under warranty.

I'd like to be part of an organized effort to work with Apple to resolve this issue.

if it involved safety, I can see a recall. Like power adapters catching fire, cars with failing brakes, etc. Otherwise, Apple will go back to their original points of reference: new hardware, clean OSX install. They might have spent 2 years refining and develping the iMac I have in my hands. If anything, we're all learning about longevity. A friend's iMac is this old school plastic thing, still runs. Don't see many of those around. Not saying they don't make them like they used to, but I am saying they're designed for a 2 year cycle. And that's amazing considering these components and their assembly took place in a really shady part of the world.

So, if those pink squares can combust your iMac, we're in business.