I have a Imac 24in 2.16 Intel chip I have a Nvidia 7600 GT 256MB card. I cant not get the unit to boot unless I boot in safe mode. I tried to do a clean OS install but even then I get the same result it boots to a Blue screen has some funny black Horizonal lines thru the mouse pointer. I've been reading about some people having problems with the graphic card on these. And I'm considering replacing that. I have no trouble opening this unit up and doing that. I work on PC's (I know yuck). But I also hear about people replace the logic board too. So Im having trouble here. if its the logic board I just dont understand how safe mode would work. well please help me I'll try anything at this point. cause a new video card is on back order from apple and could be a month away.