Hi. I have a new iMac G5. It has worked properly for three months, but lately the screen has begun to flicker sporadically, just faintly but still annoying. Yesterday the screen went completely black. I tried restarting, the chime sounds and the white light tells it is on sleep, but nothing comes on the screen. Sometimes I see a faint shadow of a window, but it's too dark to discern. I have guessed that maybe the screen brightness is set to completely dark, but since the G5 keyboard does not have a button to adjust brightness and there is nothing on the screen, I cannot verify if it's indeed the brightness of the screen that has gone wrong, or if it is something else. Can anybody point me in the right direction?