A friend had a problem with his laptop (Packard Bell Easynote) that windows would not load up properly, he gave me the laptop to have a look. It had no battery with it when i got it so i plugged the power cable in and turned it on, the lights came on and the fans spun but nothing came up on the screen, just blank. I took the HDD out and fixed the windows problem in my own PC, but now i cant get anything on screen, i plugged in my monitor and got nothing. judging by his system restore it had not being turned on since christmas time. I put a cd in and i could hear it spinning, i cant really hear the hdd but it is quiet anyway. i had a quick look for the cmos battery but couldnt find it, i also pressed function and all the different f keys when i turned it on but still nothing. another thing is it turns off by just pressing the power button without holding it down. I have also tried booting it using a knoppix disc.
It could be a variety of issues. Perhaps the inverter went out (is the backlight on the screen turning on?) or the backlight went out. You can see if the backlight went out by holding a flashlight up to it when you turn it on and see if you can see anything. If that is a no go, I would guess that it is something hardware related that malfunctioned, especially since you aren't able to get anything on the external monitor.