After ardous work and research I concluded that my LCD on my DellInspiron 9300 was bad, the dreaded vertical black line. I have purchased two LCDs from outside suppliers. Both of the LCDs worked, but the backlights never came on. The model of the LCD was LG LP171WU1 TL A2. With a flash light I could see the image, but it was not backlit. I figured it was the inverter. Using my old inverter from my LP171WU1 A4 the new screen did not light. Using a new inverter with a second new screen the same result.

Does Dell block you from using non Dell parts? This makes no sense to me that two seperate LCDs had bum bulbs. Really? 

I originally had the LP171WU1 A4. I am going to go crazy1!!