NEC LT240 - Manual (Page 41)

E-41
Press and hold the SOURCE button for a minimum of 2 seconds, the
projector will search for the next available input source. Each time you
press and hold the SOURCE button, the input source will change as
follows:
→
RGB1
→
RGB2
→
Video
→
S-Video
→
Viewer

If no input signal is present, the input will be skipped. When the input
source you wish to project is displayed, release the button.
PROJECTING AN IMAGE
Ͼ
Selecting a Source
Detecting the Signal Automatically