if it sold at micro center or alrge computer store near you first. micro center has a great return policy. next would be newegg and tiger direct. amazon not bad if your buying from a known good seller. the problem with computer parts now is they dont burn them in like they did a few years ago. they ship whole containers of mb and a few of them are doe units. i gotten doa monitor from best buy before a few years ago. yes it a pain to rebox and return doa items but they do happen.