Having problems with our iMac that we've had for several years. Yesterday, my son was using it and then he said it just froze up. Unplugged it and turned it off and back on again and saw at first a grey screen with the wheel spinning around and usually after that it would go to the login screen but instead it went to a light blue screen. Luckily, I am able to go into safe mode fine but from there I am not sure what else to do to fix this. I did try the Repair Disk in the Utilities section and it did find some stuff there that was fixed, but then I tried to restart it and still has a light blue screen Any ideas on what could be wrong?