Hi,
It seems like a case between the display or the graphics card. Here are some troubleshooting steps to identify which one is faulty.
- First connect an external monitor into your laptop and see if the same problem will persist on it because if it does that means it's the graphics card that is faulty but if it's not happening on the external monitor that means it's the built in display.
- What you can do is to reseat the ribbon cable that connects the display to the motherboard if your comfortable in opening your laptop.
- If this will not work the only solution is to replace the display itself.