Hi, I have a MacBook Air with OS X Yosemite and I can't mirror my computer on a TV (HDMI cable) ou a projector (VGA cable). First problem: when I plug the cable, it doesn't connect automatically. Second problem: all the tutorials I read ask to go to "System Preferences" --> "Displays" --> "Arrangement". I turns out my computer doesn't have this "arrangement" button on display settings, just the "display" and "color" buttons. I've tried everything and don't know what to do now. I know the problem isn't the computer or the cables because a unknown men was able to connect my computer, I just didn't see how and I can't find him again. Please, help me.