2009 27" iMac screen artifacts. Make iMac unusable, Please help

Question

27" Late 09 iMac, Was running Mavericks and Mountain Lion, i7, 8gb Ram, ATI RadeonHD 4850 512mb
About 2 weeks ago i had a random issue where my screen was displaying some odd artifacts. I tried resetting everything, unplugging it, etc and finally out of no where it was back to normal.
Yesterday it started happening again but this time, I could not get rid of the artifacts. Let me explain what it is doing.
The screen at random times will have black spots, icons will be black, some are fine. If i open a menu, The menu will be so distorted that you cannot even read it. At times the mouse pointer will disappear and various areas. Its never the entire screen, only various area of the screen, like say the icons on the dock, or drop down menus, sometimes the entire page on the screen is black.
The issue is so bad that it makes my iMac unusable. The only way i am able to do anything is boot into safe mode BUT now after a few days, Its starting to happen in Safe Mode now.
I have done everything possible from doing a clean install of Mavericks, Totally formatting HD and going back to Mountain Lion. Unplugging all USB devices and HDs, PRAM reset, SMC reset. I have tried different resolutions, etc, etc. You name it i have tried it.
It took me almost 2 hours to install Mountain Lion and Mavericks because once the OS is done installing and you have to go thru the setup screens ( choose your country, your wireless, your apple ID, etc ) half of the screens were blacked out or distorted and you couldn't even see what it was asking you to do. I have to use voice over the entire time to select and enter all my information.
Everything on the iMac works perfectly fine, The problem is, You just can't see 75% of what your doing.
Since i am out of warranty, What can i do? I assume Apple will not fix this issue for free and i assume its a hardware issue? From what i have read everywhere my guess is the graphics card is going out.
Can anyone suggest any fixes? or what the best thing is to do? I have no idea what it will cost to fix and then if its even worth putting the money.
Any help or advice would be great, Thanks.

Answer 1

mafmmx wrote:
27" Late 09 iMac, Was running Mavericks and Mountain Lion, i7, 8gb Ram, ATI RadeonHD 4850 512mb
About 2 weeks ago i had a random issue where my screen was displaying some odd artifacts. I tried resetting everything, unplugging it, etc and finally out of no where it was back to normal.
Yesterday it started happening again but this time, I could not get rid of the artifacts. Let me explain what it is doing.
The screen at random times will have black spots, icons will be black, some are fine. If i open a menu, The menu will be so distorted that you cannot even read it. At times the mouse pointer will disappear and various areas. Its never the entire screen, only various area of the screen, like say the icons on the dock, or drop down menus, sometimes the entire page on the screen is black.
The issue is so bad that it makes my iMac unusable. The only way i am able to do anything is boot into safe mode BUT now after a few days, Its starting to happen in Safe Mode now.
I have done everything possible from doing a clean install of Mavericks, Totally formatting HD and going back to Mountain Lion. Unplugging all USB devices and HDs, PRAM reset, SMC reset. I have tried different resolutions, etc, etc. You name it i have tried it.
It took me almost 2 hours to install Mountain Lion and Mavericks because once the OS is done installing and you have to go thru the setup screens ( choose your country, your wireless, your apple ID, etc ) half of the screens were blacked out or distorted and you couldn't even see what it was asking you to do. I have to use voice over the entire time to select and enter all my information.
Everything on the iMac works perfectly fine, The problem is, You just can't see 75% of what your doing.
Since i am out of warranty, What can i do? I assume Apple will not fix this issue for free and i assume its a hardware issue? From what i have read everywhere my guess is the graphics card is going out.
Can anyone suggest any fixes? or what the best thing is to do? I have no idea what it will cost to fix and then if its even worth putting the money.
Any help or advice would be great, Thanks.
Run Apple Hardware Test in Extended Mode at least 2-3 times back to back, if errors occur then you have a hardware problem. This means it is in need of repair and there is nothng we can do to help on this forum.