LG RH4820W, Service Manual

Page: 20 / 150

3-8
IC808,809 (AUDIO SWITCH) Power and switching operation
Pin 2,4 High/Low =>pin 7 output : SW_A_OUT_L/R
When playing DISC , no
audio output> check Audio output even when
Playing Disc
IC808,809-3
Check audio signal input
IC804 - 23,27
Check audio signal output
IC804 – 10,16
Check audio signal input
END
Q803 2(Emitter ) High?
IC702 - 46
LOW:AUDIO MUTE
JK803-2,6
Check input
IC808,809 - 7
Check audio signal output
NO
NO
NO
NO NO
NO
NO
YES
Check IC808,809signal
flow and power
IC804 - 32,33
Check I2C signal flow IC804 – 9:LOW?
HIGH: AUDIO MUTE
IC804 - 32,33
Check signal flow
YES
YES
YES
YES
YES
YES
8. No external input 1 audio