Don't know if your problem was solved or not, but any time your laptop turns on and stays on (LED lights remain lit), but you have no video on the screen, the first thing you should do is try to isolate the problem to either the LCD and it's components, or the video card (or motherboard if the video is integrated).
Try plugging an external monitor into the external video outlet. When you start the laptop, ... IF you still have no video, the problems lies with either video card or onboard, integrated video. If the video is integrated into the motherboard and you still have no video output to the external monitor, the motheboard will need to be replaced, ... unless there is an unused slot (or daughter board) where a video card can be installed. If there is a slot where a video card can be installed, you can just install a good video card and your video issue should be resolved.
If you get a good video picture on the external monitor, the LCD and/or one of its components will be bad and need to be replaced.