Having been dropped, the laptop would no longer boot.
The hard disk is fine (I tested it in another laptop).
When the laptop is turned on, the lights go on. The hard drive whirs and clicks a couple of times and then stops. Nothing appears on the screen at all, and there is no further noise from the hard disk.
I don't think the screen has been damaged; I think it is something else which is preventing the computer from booting, even as far as the bios.
Can you please suggest some other possible causes?