So over the last, oh lets say year, my iMac has been randomly not coming out of sleep mode and then was beginning to freeze up while awake(though the mouse moved around just fine, nothing else was interactive. So finally last Friday it went and would no longer boot up. So a brief amount of investigation tells me, most likely the GPU. So I researched and found that it would seem that the max iMac card that can be fit in my Late 09(a little snipping of a plastic support), and that’d be a pretty big jump up from the Radeon HD 4850, is the 6790m from the '11 iMac. Cost about $320 and maybe two hours of time. I could try figuring out how to reflash a regular PC version and stick even better(and expensive) cards in there but can’t spend that money now. More and more digging finally reveals, someone on bithub has collected and has linked to the AHT(Apple Hardware Test) that got canned back when OS Yosemite dropped it for the online versions. Made a bootable USB drive and ran the tests(normal was 6min, long one was 3 hours. Turns out, the only error is coming from the HDD cabling. So now with a tool kit coming in and armed with some compressed air, I should have this on lock down in opening the iMac and that should hopefully settle this matter(still wished I’d had the cash to upgrade everything else.)
Gonna edit this in: