Receiver & Speaker Trouble - LG KE820 Service Manual

5. Trouble shooting
5.6 Receiver & Speaker trouble
Check Points
-Speaker spring contact
-Audio amp soldering
-analog switch soldering
3V3_AUDIO
U208 NLAS5223BMNR2G
1
VCC
2
SPK_N NO1
3
SPK_RCV_N
COM1
4
SPK_RCV_SEL IN1
5
RCV_N NC1
C242 C240 C244
100p 100p 0.1u
3V3_AUDIO
U211 NLAS5223BMNR2G
1
VCC
2
FM_SND_R
NO1
3
AMP_IN_R COM1
4
FM_BBP_SEL IN1
5
BBP_SND_R
NC1
C251
0.1u
Check the contact spring
tension and dust on the
contact point
10
SPK_P
NO2
9
COM2 SPK_RCV_P
8
IN2
7
NC2 RCV_P
6
GND
C243 C241
100p 100p
AMP_IN_R
AMP_IN_L
10
NO2 FM_SND_L
9
AMP_IN_L
COM2
8
IN2
7
NC2 BBP_SND_L
6
GND
Check signal
flow via
Inductor
Check Audio
amp, In output
signal
Check the
analog switchs
2V72_IO
C239 220n R436 0
C245 220n R437 0
SDA
SCL
R229 100K
C247
0.1u
- 86 -
3V3_AUDIO
C238
C236 C237
0.1u 1u
4.7u
B4 D1
PHONE_IN MONO+
D4 B1
RIN MONO-
E4 D5
LIN U210 ROUT
LM4845
B5
NC1
A2 D2
I2CSPIVDD NC2
A1 E5
SDA LOUT
B2
SCL
B3
ID_ENB
E1 E2
I2CSPI_SEL CBYPASS
C248
470n
SPK_P
SPK_N
HS_OUT_R
HS_OUT_L
C447
0.22u