Samsung MH15NSSS-XAX - Manual (Page 31)

케이블 연결
User Controls
3. Volume
When OSD is not on the screen, push the or button to adjust volume.
1. Push the button to decrease the volume.
2. Push the button to increase the volume.
4. Channel
When OSD is not on the screen, push the or button to select channel
number.
1. Push the button to decrease the channel number.
2. Push the button to increase the channel number.
This function is available in TV mode only.