I'm trying to set up my Acer X223W as a secondary screen for my Late-2010 Macbook Pro, but I'm having problems doing so. The display's resolution is 1280x1050, and that is what System Preferences automatically selects when its plugged in. However, at that resolution, the screen of the Acer external display is totally black, as if it's turned off. When I change the resolution, however, to something like 1600x1200, the display works as expected. However, I want to use the native resolution of the display, because 1600x1200 looks fuzzy. Does anyone know what the problem is here? Is it my Mac or the external display? EDIT: After messing with the display settings for a few minutes, I got it to work at the native resolution, but now it does this weird thing where it turns on for 2-3 seconds, then turns off for 2-3 seconds, then turns back on for 2-3 seconds, and then turns off again for another 2-3 seconds, etc. What is causing this bizarre behavior?