Question : Problem: LCD Monitor on Laptop very faint

I have a client laptop which is about 18 months old.  It is an HP Pavilion DV9000 Laptop.  it has a 17'LCD Screen.
The laptop boots up fine.  The issue is with the Screen in that you can barely see the faint screen that appears on the laptop.  If an external screen is plugged into the laptop it works fine.  I m presukming it is either the inverter or the backlight on the laptop screen.  Is anyone able to tell me how I determine which one it is.  Can this be done by viewing them or is it a process of elimination?  Can the backlight be replaced on these units?
A new screen is quite pricey and almost equivalent to what the laptop is worth so not sure if it is economical to replace the entire screen.  I have the LCD in pieces but can not see naything that looks faulty.
Thanks

Answer : Problem: LCD Monitor on Laptop very faint

It was the video card on the motherboard.  Thanks