3 ms·13-inch or 15-inch? If 13-inch, you may have a bad HD cable.by abrowne 13y ago13-inch or 15-inch? If 13-inch, you may have a bad HD cable.jokoon 13y agoand whre do I get a new one ?abrowne 13y agoAt an Apple Authorized Service Provider or Apple Store (https://locate.apple.com/ https://locate.apple.com/). You can't usually visually identify a bad one, so I wouldn't buy one used.