No backlight - how to test the inverter?

Well thanks mayer, but it was clear that the screen worked.

The problem could be located in three places: the inverter cable, the inverter, the white-pink cable going from the inverter to the screen.

I suspected the white-pink cable, so I peeled off some bits to try and pull the copper wire. But the copper wire was not broken.

I examinated then the inverter cable. When I tried to remove it, I found out that two of the four wires were cut.

I ordered a new one, and once installed it, my light is back again.

And it was not the inverter ;-)