And there you have it folks. The Samsung/9C5B MacBook screen has a serious problem with horizontal lines on many different colors. The LG/9C5F MacBook screen looks just fine. And I've looked at about 20 different MacBooks in my city. Every single one of the Samsungs showed this problem, and every single one of the LGs looked okay. The Samsungs constituted slightly under half of the total.