Hey! I just tried update my memory on macbook pro 15' 2.8Ghz from original 4GB RAM( 2x2GB RAM) to 8GB( 2x4GB RAM) this kind: http://www.amazon.com/Kingston-Modules-1066MHz-KTA-MB1066K2-8G/dp/B001PS9UKW I follow everything that I should do acording youtube tutorial.... after replacing for new memory and turning on macbook pro I can here only beeping deep sound from my mac, the screen is black and nothing is turning on. so then I tought that the memory is wrong so I put back original ones and after I turn on, all I could here was only beeping deep sound and black screen. so I take of one of the memories ( leave one slot empty) and computer started normaly without problem. so then I put just one of new memories and macbook pro started normaly I dont know if I messed up the ram slot or what, but I tried to be very gentle while I was instaling ram... Can anyone help?