I have an HP laptop and use an older external LCD monitor. The monitor
works fine... as long as the laptop lid is open but goes blank and says
"mode not supported" if I close the lid. I have the laptop settings (Vista)
to "do nothing " when I close the lid. Might I have another setting that is
off somewhere?
It probably depends to some extent on your graphics chip & driver.
My laptop (a Dell D630) has an nvidia graphics chip. I use it in a
docking bay (actually it's the little one - I think they just call it
a port adapter), which has 2 video out connectors, each of which is
connected to a monitor.
In my power settings, I make sure that it's set to "Do nothing" when
the lid is closed and the power is plugged in (make sure you haven't
just set it to do nothing when you close the lid when it's on
battery).
Then I configure the displays using the NVidia Control panel software
- when the laptop isn't docked, the software recognises that, and only
gives me the laptop screen to configure, but when it is docked, I can
configure the external monitors. It might be that you have to connect
your external monitor, leave the laptop open, configure the display
settings, and then close your laptop. Hopefully the machine should
then remember these settings (the NVidia software does a reasonable
job of this but tends to forget which monitor is in which position).
One more thing - some laptops have a setting in the BIOS which
determines which screen has priority. If you have it set to use the
laptop screen as the primary one, then perhaps your machine is
selecting that, but turning it off because the lid is shut.
