Samsung SP-D400S - Manual (Page 23)

Connect [PC IN] port on the rear side of the projector to the monitor output port of the PC using a PC video cable.
When connections are all completed, connect both power cords of the projector and the PC.
This product supports plug and play, therefore you do not need to install a driver on your PC.
Using the Projector
Turn on the projector and press the [PC] button to select <PC>.
If PC Mode is not available, check PC video cable is in place.
Turn on the PC and set the PC Environment when necessary.
Adjust the screen.( Auto Adjustment )
Sound comes out from PC speakers.
Connecting Video Devices (Monitor, TV, etc.)
- When using the D-sub (analog) output through another video device (monitor, TV, etc.).
Connect the PC OUT terminal of the projector and the D-sub terminal of the video device using a
D-sub cable.
After connecting them, turn on your projector and the video device (monitor, TV, etc.).
The PC OUT function only operates when the projector is connected to an external device through the [PC IN]
input terminal.