Backlight isn't working at all

I've read some other guides of people with similar issues but none of them are exactly the same. The backlight on my macbook is completely broken. It won't flicker on or light up no matter what I do. I've tried decreasing the brightness and bringing it back up, I've tried resetting the PRAM and taking out the battery, and I've tried messing with the energy saver preferences but none of it helps.

The computer itself works fine - if I shine a flash light on the screen I can see my desktop and I've been able use the internet and do everything I normally do.

A couple of months ago, I replaced the inverter cable because the backlight would go off unless I kept the screen at certain angles. The "surgery" went fine and the backlight worked great for awhile but stopped working literally overnight (watched an episode of Dr. Who that night, wouldn't work the next morning). I can't think of any other relevant information but I'm happy to answer any questions about the system. Thank you in advance for your help!