No display on Compac Evo N800w

I'm working on a Compaq Evo N800w that has no display. In fact when I power it up I don't even hear the hard drive spinning. On every other laptop I've working on I can hear or feel the hard drive spinning.

And I have a Dell Inspiration 1150 that the screen is very dark but it does come on and I can run programs, it’s just too dark.

I also have an HP Pavilion dv1000 that has a dead battery and the plug in is broken off. I think I need to buy the plug in a solder it on...the only problem, I don't know how to solder. Any soldering guides will be appreciated.

Please help!

 

Compaq-do you have any air coming out by the fan vents? If not, and there is no lights on I would say its a power supply issue, maybe even some bad/bulged capacitors on the motherboard.

Dell-Sounds like the back light has gone out

 

Compac-I'm sorry I forgot to mention that yes it has the power light on and fans running.

Dell-That's what I thought...how do you fix a backlight.