A day or so ago, i asked how to reset the battery to remove the bios password, at first when i did it, it worked for a while but then the password came back. So i took the battery out for longer, even longer for literary 9 hours whilst i was at work. When i came back, i inserted the battery and powered the laptop on only to find that the fans would spin up but only a black screen would display.
Does the backlight even power up? (will still be a black screen but in a dark room you should be able to tell if it's lighting.
Also try letting it run for a bit then see if Caps Lock cycles when you press it (does the light come on) or try an external monitor / tv. Maybe also try hitting FN (output selection key usually f4ish).
Can you get into your bios, or is the screen not even turning on? If you can get in, check your settings. It's possible the reset changed something that is preventing your computer from booting.