I just bought a new imac 27", later half hour of use I noticed it has a little scratch on the screen, not on the front glass but behind it. too strange to be some dead pixel. Someone can tell me what is? Do AppleCare cover this? If they do, has to be exchange the whole machine or just the display? here is some picture:
It looks to me like a row of pixels but in any event you must return it within the 14 day period (or at least have a formally confirmed agreement that you will be doing this). The latter applies if you live too far away from a suitable returns venue and it has to be returned by carrier. Usually all carriage costs are covered.
It would be better if you return it for a full refund. That way you can order or purchase another brand new iMac and won't incur an early repair on a brand new unit. If you can't return it on time when you get back, you can use AppleCare. They will do a repair or replace the part, not the whole iMac.