One of the most common reasons why a laptop screen goes black is because of impact damage. This can happen when the laptop is accidentally dropped or bumped into.
Apart from a cracked screen & display chip damage, the whole monitor goes black and doesn't respond when turned on.
If the damage is superficial, you can get away with simple screen replacement... Get a replacement screen from Ebay and install it in place of your damaged laptop screen.
I've done this on laptops ranging from Dell, HP, Acer and Toshiba. Just make sure you get a screen that's compatible with the monitor size & cable connectors of your current laptop.
Turned on your laptop and horrors upon horrors, the screen is BLACK! You see that the laptop has power but besides that nothing is happening, Means that there is a very good chance you can get out of this situation quickly and without any cost. This fix works on all brands of laptops:
Take Out Laptop Battery
Remove AC Adaptor Cord, that's the wall power, remove it.
Hold down the power butten for nearly 30 seconds
That will drain any static electricity that has built up on your laptop system board and many times fixes the problem of a black screen. After the 30 seconds re-connect your laptop to the wall power and push the power button normally and see if the laptop comes back up. Replace your battery.