i'm going to the apple store in columbus, ohio on saturday to maybe purchase a iMac i5, if i find a good one. new to mac so could someone please tell me how to check to see if screen is ok. i am going to check in the store before i bring the unit i5 home. it is a 4 hour drive but maybe this will assure i get a good mac. also why do the one displayed in the stores look good or am i missing something. maybe if i knew how to test i could test the displays also...lol but i need exact instructions to test in the store this will be my first mac....thanks so much...