If your screen is black, here what you can do to check if the machine is even running or not. [br]
Do you see the fan running for a while, something is happening in back that you can’t see? if so, then you can try plugging any VGA or HDMI cable to see the output of the machine on another display to just isolate the issue. [br]
in case if the output on another display works, then you know that’s just needs new display on that machine.
Not even turning on at all? such as fan or any sort of the noise that makes you feel the machine is on. If machine is not even (responding) to any activities when you press power button, it means that there is no power given, either button is not working, or adapter is not juicing the battery, so you will have to isolate the issue first to drive this troubleshooting first.