Strange LCD issues out of the blue

Can't say for sure what the cause would be but if I had to guess it would be physical damage to either the screen or the connection. Might want to make sure the socket (at either end? not a Laptop expert) is clean and that the cable is intact and well seated.

You can bring it to a PC/laptop repair shop in your area to find out if and how much to replace. Sometimes getting the screen replaced is close to the price of a new laptop so best to check for a price before leaving it with them.