Please do try these troubleshooting steps that may help.
- Start by connecting an external monitor and see if the same problem will persist or not.
- If the problem does happen on the external monitor that means it's related to the GPU and a repair is required.
- If it doesn't happen on the external monitor that means it's just the built in display that has the problem.
- You may need to open your laptop and check if the ribbon cable is properly seated on the LCD and the motherboard.
- If these will not work replacing the LCD would be the only solution.