I am getting a white screen on my laptop but if I connect the laptop to a tv, I can see my windows screen

[Cathboo]

I am getting a white screen on my laptop but if I connect the laptop to a tv, I can see my windows screen

 

[Illumynization]

The board for the screen is defective. The inverter for the lcd back light is fine. This outputs a white light with no picture. You need a new board (sometimes the board and screen are sold as one unit).