New screen and inverter still dead

[kennedy4121]

I was told the screen was bad on our HP Pavilion dv4-1220 laptop so I installed a new screen and inverter. Still is dead< nothing happens. Laptop works when connected to an external monitor. Any ideas what else I can try? The driver for the video card is current. Thanks Larry

 

[twelve25]

bad cable?

 

[popatim]

If the florescent tube isnt lighting up you should probably check the input voltage to the inverter board.