I'm going to have to disagree with Jazzman, there is no serial cable going to a laptop monitor.
What there is a "flex-bend" circuit board connecting the display to the video output on the motherboard.
The only way to test a laptop display that I know of is to connect it to a working laptop.
Great care must be used when disconnecting the "flex-bend" circuit board from the MB.
There is a usually a connector release device that need to be released
during removal.
They vary in design but are usually plastic clasps or tabs that keep the two connectors together.
If you pull the "flex-bend" circuit board out of its connector it's almost imposable to put it back in.
