need help with screen on HP pavillion zv5000?

Hi,
I have two HP pavillion zv5000 laptops and both are bust! On one the laptop screen is completely black, you can see the lights going when you power up so I'm assuming its loading up ok, just that i can't see anything. Would anyone be able to give me instructions on what to do to fix it?
On the other one the screen comes on but I cant see any of the windows Icons on the desktop to get into it and have no idea how to sort it, not sure if its a virus or what? Please help if you can. Thanks