This sounds like what i had www.tomshardware.co.uk/forum/75534-20-display-picture
I would make sure that your
lcd cable is working correctly.
Inverter is working.
If you have replaced those try the " fn+f5" key i think to swap screens, if there is a white glow on your LCD it means the lamps are working / your inverter is working.
If those fail i think your mainboard may need to be replaced as the GFX for this laptop is an intel GMA965 chip..
hope this helps.