How do I get rid of the vertical lines?

I have a Samsung UN65NU7300FXZA with vertical lines. The thin vertical lines,of all colors, start to show up appropriately 20 seconds after I turn my TV on. One at a time and in two specific areas of the screen. Since it didn't get these lines until a short period after I turned it on I thought maybe it was heat related. So,the first thing I did was grab a small house fan and pointed it directly at the pier supply board. Sure enough the lines dissappear one by one in the exact opposite order they appeared. If I keep the fan there the lines stay away permanently and I can watch TV for any length of time. Removing the fan brings the lines back immediately. Now, I know I can buy a small cooling fan to prevent the lines. But does anyone know exactly whats going on here? And how to fix this without having to use a fan?