display or lcd problem .

I am seeing some issues with my display, like if I play YouTube for an hour or two on Google Chrome and switch from YouTube to another app or any other site, I still see a shadow or mark of the YouTube logo and the part of the display where the video was playing. Not just YouTube, after running Facebook or any other application and exiting it, I also see light traces of those applications on my screen. But the LCD test given on the laptop does not show any such issue. But I face that issue while running any other application. These marks go away if I keep the laptop closed for 2 to 3 hours. Now tell me how can I get rid of this issue?