Hi My imac from 2009 suddenly shut down. a week ago I had a little electric shock touching the screen frame of the imac. It was more than static electricity because it was there several times when I touched it. The imac wasn't turned on but was plugged into the power socket. I turned off the power on the wall and turned it on again and I didn't get shock anymore when I touched it. Since then I've been a bit worried touching it but it's been ok this past week, then suddenly tonight it just shut down all of a sudden and I'm afraid to turn it on again. Nothing else shut down. Can anybody help?