Your issue actually sounds like a bad inverter, a backlight would either leave the screen uniformly dark or light in areas, you would not see horizontal lights like this. Unelss you maybe have an LED backlight which are pretty rare now.
After the inverter change, does it all look exactly the same? You may have damaged the LCD screen itself. Was this dropped, gotten wet, etc...?
If you checked all the cables and installed the inverter properly, next step is replacing the LCD panel.