Sadly, lines are usually caused by the cable no longer having a good connection to the panel. See, modern manufacturing practices are such that nobody takes the time to actually solder wires on anymore, so they are just held on with tape! Over time this tape gets loose and causes poor connections, leading to all of the LCD screen and CCD sensor warranty repairs you have probably heard about. So the tape is designed to last just through the warranty period and contributes to the disposable, throwaway nature of modern consumer products
The usual fix is to iron the tape back on using a soldering iron and silicone pad. You can find the kits at Amazon by searching for "LCD Pixel Ribbon." It is not possible to actually solder the wires...