Hello everyone, (I also want to mention thag I'm a newb with iMacs) I have a problem. My iMac 27" mid2011 screen is completly black - its not turning on. So what have I done before my problem, was to clean the formed "dust" that was on that white panel and that see-through panel. Now everything is connected, but the screen wount turn on.. I can hear the chime sound and the fans working after I press the power button. I would be glad if anyone could help me fix this. Regards, Sam.