lcd has green lines that appear and disappear when touch?

a friend has this phone, when using it its fine, but if you leave it for a while green lines are shown from top to bottom, you can see is lcd fail but they all disappear if you touch the screen, touch works perfect.

i have done some repairs but this is the first time i see it.

thanks guys.

p.s. he of course has no matrix theme as wallpaper ;)p