How to turn off internal monitor when using external one
I've been given a Dell Latitude C640 laptop as my work PC (it was
formerly used by my boss, who ran Windows). When in the office, I
plug it into its docking station under my desk and use external LCD
monitor, keyboard and mouse. I run Sarge, kernel 2.6.8-1-686.
My problem is, when it's plugged in, the internal monitor is blank
(which is fine for me) but on, regardless whether the lid is open or
closed, and that heats the laptop quite a lot, especially since I
usually keep it closed. A colleague told me she used to have the same
problem, and her motherboard burned after some months; after that she
switched back to Windows.
However if I switch to the text console (even if X is running in the
background), the internal monitor does turn off. Thus I suspect it
could be a problem of configuring X correctly. I guess that I should
somehow tell X that I have two distinct monitors, and want to use
only one of them. But I don't know how to do that.
Anybody could help me?
Thank you very much.