Iiyama ProLite LE4262S-1 User Manual page 19

 Adjust the volume of sound
Press the / Button on the Remote Control to adjust the
volume of sound when the menu page is not displayed on the
screen.
 Switch the input signal
This is activated when you successively press the SOURCE
Button on the monitor or INPUT SIGNAL Button on the
Remote Control as follows:
[Monitor]
[Remote Control]
YPbPr
[Remote Control]
YPbPr
BEFORE YOU OPERATE THE MONITOR 15