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:
- The quantity of squares and if they flash or are still seems to mostly be related to running more applications / using up more memory.
- The squares are not seen when logged into a game, watching a DVD or change a program to full screen.
- If I let the iMac simply load and sit for a while w/o opening applications I sometimes still see the squares.
- 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).
- If I jump to a second desktop, the squares disappear temporarily but will start flashing again.
- 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:
- Used a different power cable (one from Apple Store) and had the same result.
- Moved the power plug to a different outlet and replaced the surge protector.
- Removed everything that was plugged into USB.
- Removed sound system that was plugged into audio port.
- Removed ethernet.
- Used only the Apple Keyboard instead of my old Logitech.
- Turned off wireless.
Squares Most Frequent While Using:
iTunes, iPhoto, Chrome, After playing a game in Steam and when using AppleScript.
Conclusions/Insights:
- In my experience, replacing the graphics card did not work.
- I have not purchased new RAM to see if that helps but I do not believe it will help with this issue.
- I am still very curious about the motherboard and/or connections to the board as that appears to have helped out other users.
- Based on responses in this thread and what I have seen, this is likely related to software / OS. Maybe a compatibility issue?
- 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).
- If this is related to a bad Kernal response, I really have no insight to fixing/troubleshooting such a thing.
- 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.
- 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.
- 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:
- Remove / Re-install Chrome
- Troubleshoot additional apps
- See if I also observe no issues in Windows 8
- Reinstall iTunes
- Take back to Apple Store again
- Maybe purchase new RAM (but unlikely unless if I have more proof that it will help)
- 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.
