It looks like the backlight of your display stopped working. It can be the light tube itself, it can be the inverter module, it can be the wiring that powers the inverter module that broke.
A backlight inverter drives the tube at some 300vac if the tube works, and to over 1000vac if the tube does not emit light. If you do not have experience at playing with this, I do not recommend that you open the laptop. Shorting this voltage to the rest of the laptop might fry the rest of the circuitry. A certified repair center for your laptop will usually have a list of the common problems for your particular model. The failure that you see is common to many laptops, so the repair people shouldn't fiddle too long before repairing it.
