An audio/video playback control system of liquid crystal display
television (LCD TV) is provided to control an audio signal system, an
image display system and a backlight source system of an LCD TV, and the
control system uses an audio/video control unit to maintain an activated
status in normal conditions, and the audio/video control unit receives a
signal transmitted from an external control interface to determine
whether or not to output an activate signal to activate the audio
processing unit or activate the video processing unit and the backlight
source system, or jointly activate the audio processing unit, the video
processing unit and backlight source system, so as to achieve the digital
control of the LCD TV and the power-saving purpose.