I just cleaned my laptop of dust by taking it apart but when I turned it on , everything went as expected. The fans work and the two LCD lights at the bottom are lit up but the screen doesn't turn on. It is not black but isn't lit up at all... Can it be something with the cable? I don't have a second monitor to see if it's the computers fault but I think it's the LCD screen.
Can you give me some advice?
Without a second monitor to test it, you won't be able to tell if it is the display/cable or the GPU. You can try opening it back up and carefully disconnect and then reconnect the display cable to see if this resolves the problem. Should that not resolve it then you need to find a way to connect an external monitor or take it to a tech to have them look at it.