Why are there lines or blotches on my Smart TV screen?

1. Check if the lines are permanent or temporary
2. Make sure the cable connections to the Display panel are snug and connected
3. Ensure the cable connections are tight and secure on both ends
4. Check for any possible flickering of the display
5. Check if there is a loose contact inside the TV or the plug is not fitted properly
6. Check if the refresh rate of the TV is set too high
7. Check if the connections are audio/video are properly connected
8. Update the firmware of the TV
9. Verify that all cords and cables are connected firmly and securely.
10. Reset the TV to factory settings