Verticle lines appearing on screen


I have recently installed Ubuntu onto an SD card, and installed LXDE.

When I installed ubuntu I saw vertical lines across the screen of varying colours, and the same thing happened when I installed LXDE. Where there is text or a graphic on the screen, the display looks ok, it’s where there a black areas that I see this problem. I have attached a photo below. Has anyone else seen this? Could someone please advise on how to solve this problem please?

Kind regards