If you have 3.3 volts on pins 1 and 5, and 0 volt on pins 2 and 4 for the U11 chip. This is the reason the backlight is OFF, you need 3.3 volts on pin 4 for the backlight to be ON. Right now the pin 2 is controlling the output for the U11. Pin 2 for the U11 is connected to the EC chip, so, what is controlling the EC to give 0 volt to pin 2 for the U11? This is why I asked to verify the voltages for the U14 chip.
do you have an email or skype id so that i can send you the photo
I reply only on this site for everyone to see the answer, never in personal mail. I don't need your photos, I told you the L4 coil is near the pin 1 at the LCD connector. I also asked you if you have a voltage on the pin 1. I provide you with a picture where is located the coil L4 on the motherboard.