Vertical lines on LG 42 inch

I get 3 to 6 vertical line on my plasma screen. They are always come in the same spot (just left of centre) and seem to come and go randomly. Sometimes they come every night, for about ten minutes at a time and sometimes they don't appear for a while. The tv is only two years old, well looked after and not over used. Any help would be great, thanks. my LG plasma has a thick 5cm line just to the left of the screen too an it comes and goes all the time, the control board how much do they cost an does it take long install? Can you order one online an do it yourself or do you have to send plasma somewhere as I live in a small country town along way from anywhere