Won't boot, gets stuck on loading screen which turns "green"

[Viira]

So its been 4 years since my last issue with this imac (ECM 2111) and it broke tonight ;[

The message popped up telling me I needed to restart, I did, now does not want to run.

It starts to load up, plays the start up chime, I see the apple and loader animation, then the screen becomes all "green pattern-ish" and again I get the message to restart

I tried the PRAM and NVRAM & SMU reset - nothing
tried loading with my original disk - nothing

What could be wrong with it?

 

[Hellhammer]

Might be the logic board.

http://guides.macrumors.com/Mac_doesn't_boot

 

[Viira]

So i was able to run the hardware test and apparently it said no problems were detected, but, the tab with video card says "unknown video"

 

[Hellhammer]

Sounds like a GPU failure then. Not much you can do. You could take it to Apple so they can troubleshoot it and give an estimation of repair cost but I doubt it's worth it to fix it.