Hey all. I have a late 2009 21 inch iMac Core 2 Duo...500GB. This thing has run like a champ since I bought it except my bluetooth went out a couple of years ago and had to be serviced. Anyway. Starting yesterday, my iMac screen will go black.... but it's not asleep because iTunes will play. I will hit the "speedometer" looking button on my wireless keyboard, and the screen will very shortly "flash" where I can see my desktop, but it won't show the dashboard, and it goes black again. I have to restart to get my screen back. I've repaired disk permissions and rebooted, but don't know what else to do. Is this a hardware issue or software issue? Thanks.