Screen Crashes with black/white Squares

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Level 1

10 points

Screen Crashes with black/white Squares

Hi just wondering if any one on here has had similar problems or can help me with this issue.

Last night i was using photoshop and all of a sudden my screen crashed and lots of White/Black/See Through Squares appeared on my screen. I restarted my iMac but when it started back up again the problem was still there so then i tried a PRAM reset which sorted the problem out, But only for a few minutes.

After loading everything back up and getting back to work on photoshop a few minutes later it happened again. Everything crashed and i had to perform a PRAM reset to get the computer working.

So after all that i thought maybe the video card or CPU was under a bit of stress so i decided to close all programs and just leave it with my desktop open and no applications running, 10 minutes later it happened again.

After reseting the PRAM 5 or 6 times this fix actually stopped working and now not even a PRAM reset would load my computer up it would just load the white screen with the apple logo and then crash.

I then managed to get back to my desktop by starting in SAFE mode, after this i uninstalled photoshop completely and then went and fixed my disk permissions.

I restarted the computer and everything loads up fine, The computer works fine for around 3 or 4 hours but just as i got my hopes up that the issue was fixed it happens again. Im stuck now on what to do, the PRAM reset only temporalily fixes it, i have tried a reset called SMC but that didn't work either.

I have attached a picture below as its pretty hard to describe what it looks like. Any help would be greatly appreciated.

iMac 21.5 (Mid 2010), Mac OS X (10.6.3)

Posted on Jun 11, 2012 6:40 AM

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Answer 1

BGreg

Level 6

17,552 points

Jun 11, 2012 7:08 AM in response to Kiz5000

Run the Apple Hardware Test to see if it comes up with any display hardware issues. You'll need the original OS X gray-faced disks that came with your system.

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Answer 2

Kiz5000 Author

Level 1

10 points

Jun 11, 2012 8:44 AM in response to BGreg

Hey thanks for the reply. I have just tried this and it came back with the results "No trouble Found"

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Answer 3

BGreg

Level 6

17,552 points

Jun 11, 2012 9:02 AM in response to Kiz5000

While the AHT isn't perfect, that says there's not an obvious hardware issue.

Are you really at 10.6.3? I would load the 10.6.8 combo update. Repair permissions first with Disk Utility, apply the update, then repair permissions again. The combo update contains all 10.6 updates and is available at the Apple download page.

Then see if you still have the problem.

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Answer 4

Kiz5000 Author

Level 1

10 points

Jun 12, 2012 4:46 AM in response to BGreg

Hi i am actually using 10.7.4 i just havnt updated my profile yet. I have since erased the whole hard drive and installed a fresh copy of lion but i still have the same problem. Im thinking maybe its a video card fault i really hope not though becuase i work from this computer and would be lost without it if i had to send it off for repairs. If it was a video card fault then wouldnt the same be happening with the screen while in safe mode becuase in safe mode its sligtly different and i can just about see what im doing. Im in safe mode right now here is a screen shot of what it looks like

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Answer 5

BGreg

Level 6

17,552 points

Jun 13, 2012 7:59 PM in response to Kiz5000

It may be time to take it into an Apple store and let them confirm if it is indeed a hardware video circuit issue ... can't keep using it like that.

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Answer 6

RRFS

Level 5

4,522 points

Jun 13, 2012 8:34 PM in response to Kiz5000

Lion works your system harder creating more heat.

As old as your iMac is, have you cleaned out the dust? Dust buildup can lead to over heating issues. Remove any and all things plugged into it including the power cord, Remove the RAM access grille. Vacuum all openings starting with the RAM access area (air intake). Vacuum all ports and plugs, DVD slot and the opening across the top of the rear of the body. Blow compressed air through all your openings and vacuum again to remove any dust you loosend. Reinstall the RAM grille. Plug in the keyboard and mouse if not blue tooth. Insert power cord...

You are now in a perfect position to do a

SMC RESET

http://support.apple.com/kb/HT3964

Shut down the computer.
Unplug the computer's power cord and ALL peripherals.
Wait 15 seconds.
Attach the computers power cable.
Wait another 5 seconds and press the power button to turn on the computer.

Here is a Widget to monitor your temps and other operations:

http://islayer.com/apps/istatpro/

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