I've got an Early 2008 iMac; model A1224 EMC 2210.

I was surfing the web the other night, and the system hung. When i forced a power down, and then restarted it, it came up with a messed up display. See the photos:





This comes up everytime i reboot now. I can't even see anything unless i go into safe mode, and then I can at least (sort of) see the menus etc.

I've tried resetting PRAM, i've reseated / replaced RAM, tried a different hard drive with fresh install of OSX, set up an external monitor and connected to iMac remotely from another Mac via VNC application and I still get the weird display no matter what.

I am determined to fix this but need some direction on what needs to be done.

I'm thinking it's the video card, not the motherboard. Thoughts?

What is my next troubleshooting step?

Thanks in advance!!