Before you start replacing parts, please hook your Mac up to an external monitor and tell us what you get. I am not convinced that your problem is the backlights. Here are the symptoms of defective backlights:

Defective CCFL backlight may have the following symptoms: Screen flashes on red/pink and goes off. Picture stays on in red and slowly be come normal. Picture flickering with dim display. Picture flickering on and off. All these symptoms indicate that the LCD backlight lamp (CCFL Lamp) has reached the end of its life.

You might need the inverter part, that's the one I swapped out in my Powerbook's screen when it went black. It's hard the actual lamps break/wear down.

Dell Laptop XPS M1530 has a screen that is getting progressively too dark to read.

yes the unit works but again it does not light up. my direct email is alsespace@hotmail.com so we can discuss those repair instructions