Hello,
Did you replace the LCD panel, or the entire display assembly?[br]
You could have gotten a defective part, but it could just as easily be a problem with the backlight output on the board (you can blow the backlight fuse if the laptop is on when the connector is removed / inserted).[br]
I would disconnect the battery, remove the LCD cable, check the end for damage, and reinsert it if it looks OK.[br]
If you are comfortable with using a multimeter and probing small things you could check for backlight output voltage.[br]
I wouldn’t attempt this if you are not comfortable however, as it is relativity easy to slip and short something out with the probe tips.