Laptop light problem?

Ok here is my delima i have a found a dell inspiron B120 in the trash and i had the same one at home needing parts i got everying things working except the screen wasnt lighting up. orignally i though the inverter was the problem so i took the one out of the other laptop and installed it in. that didnt work so when i looked in the back the backlight was shot so i ordered a new one online and resodered it in. But the screen nor the bulb will light up still and im scratching my head plz help ty.