Can you see anything on the screen when you move the lcd, it more sounds like the backlight has just gone faulty. This would make the lcd appear to have no picture, but the image is there but without a light behind it, have a close look at the screen and see if you can see anything. If that is the case then sometimes the backlight should just have a fuse on the inverter pwb which can be tested and replaced if needed, if not then more expert help may be needed
Simon
September 2006