Hi, new to the forum but thought I would try to get some advice.:Blushing:
Problem - iMac boots and gets to desktop - but shortly after glitches with purple and green squares flashing over screen and freezes within a minute or 30.
I have been using it in target display mode with a windows pc since the start of the year (when the freezes started) no problem as long as I get time to press command F2 to put it in target display mode.
I haven't used it as a desktop for a fair while but I can launch a game (Bioshock 3 at start of year was the last) and it will run fine until I go back to desktop, mysterious.
I have now bought a nice new 30 inch monitor to use with the pc and want to fix the iMac to use as basically a web browser/pdf viewer.
Anyway I am pretty sure it is a failing video card after doing some research on the topic. The problem is my research only really turned up people wanting to upgrade video cards but I want the cheapest card that will work.
So I am willing to spend say around $150 - I am also willing to take some risks around compatibility and have taken the screen out and been at the graphics card before when it first stopped working and don't have much to lose.
So what is likely to work and what are the cheapest options.
Been looking at different laptop cards that match those that apple used in models from 2009-2011, but don't want to take the plunge without some advice.
Could I use this from ebay and I know this wasn't used in an iMac but I could perhaps use some kind of hackintosh kext.
Any help would be awesome!
Problem - iMac boots and gets to desktop - but shortly after glitches with purple and green squares flashing over screen and freezes within a minute or 30.
I have been using it in target display mode with a windows pc since the start of the year (when the freezes started) no problem as long as I get time to press command F2 to put it in target display mode.
I haven't used it as a desktop for a fair while but I can launch a game (Bioshock 3 at start of year was the last) and it will run fine until I go back to desktop, mysterious.

I have now bought a nice new 30 inch monitor to use with the pc and want to fix the iMac to use as basically a web browser/pdf viewer.
Anyway I am pretty sure it is a failing video card after doing some research on the topic. The problem is my research only really turned up people wanting to upgrade video cards but I want the cheapest card that will work.
So I am willing to spend say around $150 - I am also willing to take some risks around compatibility and have taken the screen out and been at the graphics card before when it first stopped working and don't have much to lose.
So what is likely to work and what are the cheapest options.
Been looking at different laptop cards that match those that apple used in models from 2009-2011, but don't want to take the plunge without some advice.
Could I use this from ebay and I know this wasn't used in an iMac but I could perhaps use some kind of hackintosh kext.
Any help would be awesome!