Hier mal ein Auszug aus meiner xorg.conf. Daran kann man sehen, wie man Ausgänge deaktiviert etc..
Section "Device"
Identifier "Card"
Driver "intel"
Option "monitor-VGA" "VGA"
Option "monitor-LVDS" "LVDS"
Option "monitor-TMDS" "TMDS"
Option "monitor-TV" "TV"
EndSection
Section "Monitor"
Identifier "LVDS"
EndSection
Section "Monitor"
Identifier "VGA"
EndSection
Section "Monitor"
Identifier "TMDS"
Option "Ignore" "true"
EndSection
Section "Monitor"
Identifier "TV"
Option "Enable" "true"
EndSection
Section "Screen"
Identifier "Screen"
Device "Card"
Monitor "LVDS"
EndSection