My iMac messed up a while ago and green lines appeared whenever I started it up. It happend in windows mode too. I can only boot into windows safe mode because I get the blue screen if I don't. I don't know what's wrong because when I was in safe mode the problem fixed itself twice and then I could boot normally. Later it went back to the green lines on the screen. I used the recovery boot option and erased the Mac partition and now can only boot into windows. Any help?