|My bad, I missed where you said you had already tried an external monitor.|
Can I take it that you never see anything on the screen at all?
This might sound a little quaint but does it "sound" as if it's booting up?
If so then, although it is difficult to be certain, the video module is prime suspect. This is inbuilt and addon cards are not usually available for laptops. Not being able to peer into BIOS makes life difficult too.
There is a technical manual here:
Always pop back and let us know the outcome - thanks