Mic / Usb / Key / Vfd Circuit Diagram - LG MDD105 Service Manual

8. MIC / USB / KEY / VFD CIRCUIT DIAGRAM

12
VFD901
LG_MCT355_VFD-A
VFD
HNA-15MM40T
11
R905
C904
100K
104
GND
F-
10
SW937
VFD
0
SW936
9
9
R963
SW935 39K
MARK
8
P18
27
SG18
P19
28
SG19
R962
P20
8 29
SG20
SW934
18K
7 30
SG21
31
SG22
32
SG23
R961
PT6324(QFP52)/ET8862
33
SW933
8K2 SG24
6
GR01 34
GR1
7 GR02 35
GR2
GR03 36
GR3
R960
37
GR04
GR4
5K6
SW932
38
5 GR05
GR5
39
GR06
GR6
R959
SW931
6 3K3
4
GR07
R958
GR08
3K3
SW930
GR09
3
GR10
GR11
R957
5
2K2
GR12
SW929
2 GR13
GR14
GR15
R956
1K8
SW928
D902
1
4 VR901
R955
SW927
1K2
ECHO VOL-
R954 10K
SW926
R916
1K2
ECHO VOL+
10K
R917
3
C916 C917
R953
SW925 473 473
1K
MIC VOL-
R952
GND
1K2 R964
SW924
2
MIC VOL+ 47K
KEY3
3
2 KEY2
1 DGND
CN906
KEY2 PCB
1 TO MAIN PCB MICOM
A B C D
VFD BOARD
R904
100K
GND
P901
FM-6038TM2-5A
GND
F+
R906
100R
13
SG4/KS4
12
SG3KS3
11
SG2/KS2
10
SG1/KS1
FB901 10uH
9
VDD
U901
8
GND
R909 82K
7
OSC
R910 100K
6
K2
R911 100K
5
K1
4
DOUT
R912
1K
3
STB
R913
2 1K
DIN
R914 1K
1
CLK
C911
100P
GND GND
GND
C913
104
C912
104
C914
47U/50V
IN4001 D901 IN4001
GND
DGND
TO MAIN PCB MICOM
E F G H
KEY1 PCB
KEY3 PCB
SW919
SW920
CD SYNC
JK901
EQ
R946
R942
SW918
18K
SW921
8K2
CLOCK
LG EQ
R945
R941
5K6
8K2
SW917
SW922
TIMER
R940
USER EQ
R944
5K6
3K3
SW916
SW923
HP JACK(3.5mm TC38-103-01)
DISCSKIP
XDSS/MP3 OPT.
R939
R900 R943
39K
3K3
3K3
JK903
MIC1
SW908
SW909
R
AUTO DJ
R924 R930
3K3 2K2
SW907 SW910
TUNNG+ TUNNG-
R929
R923
1K8
2K2
SW906
SW911
STOP
SET/CD PAUSE
JK904
R922
R928
MIC2
1K8
1K2
SW905
SW912
PRESET+
R921
PRESET-
R927
1K2
SW904
1K2
SW913
OPEN/CLOSE
POWER
R920
LED BOARD
R926
1K2
SW903 1K
SW914
AUX
USB/DEMO
CON1001
R919
R925
1K +12VA
SW902
1K2
VOL_LED7
SW915
TAPE VOL_LED6
DVD
R918
VOL_LED5
1K2
DGND
SW901 VOL_LED4
VOL_LED3
TUNER
VOL_LED2
DGND
VOL_LED1
VOL_LED8
Q901
9014
Q902
9014
R931 10K
Q903
9014
R932 10K
10K
R933
R934
10K
R935 10K
R936 10K
R937 10K
R938 10K
I J K L
3-39 3-40
HEADPHONE
C924
6
TO MAIN PCB PWM
FB922 JK902
100M 70R
CN904
5
USB SOCKET
1 HP-SENS
6
V+
FB904 3.3uH
7 4
D-
2 HP-L
3
D+
2
V-
3 AGND
2 1
FB903
5
4 HP-R
3 3.3uH
4
GND
FB902
GND
1
USB/PHONE BOARD
100M 70R
MIC BOARD
6
5
4
R950 22K
2
3
R973 56K
7 R975
100K
8
C920
9 104
GND
R974
1
56K
6
5
R951 IC1
4
22K R977
S4308
2
10K
1 NF VCC
3
C3 2 GND ALC
C923
7
R976
3 INPUT OUTPUT
682
104P
8 100K
C921
BAN57059401
9 R5
104
100K C2
1
NC
GND
104P
GND
GND
GND
R923A R926A R927A R928A R929A
471/0805 471/0805 471/0805 471/0805
471/0805
D916
D915 D914 D913 D912
1 BLUE BLUE BLUE BLUE
BLUE
2
3
4
5
6
7
8
9
Q904
9014
Q905
9014
Q906
9014
Q907
9014
Q908
9014
DGND
M N O P Q
104
0R CN901
FB223
USB_GND2
FB905 1
2 USB_VCC
0R
D-
3
D+
4
C919
220U/10V
5 USB_GND
TO MAIN PCB ESS
TO MAIN PCB ESS
CN905
MIC_SENS
1 MIC_SENS
MIC_OUT
2 MIC OUT
GND
3 GND
+12VA
4 +12VA
L1
FB2500
100K R4
C6
R1 100uF
16V
220R
R6
6
1K
5
R2
47K
4
C1 NC
R3
220R
C5 C4
C8
100uF 1uF R7
16V 50V 1M
C7
22uF
16V
GND GND
GND GND
R939A
R938A 471/0805
471/0805
R940A
471/0805
D910 D918 D917
BLUE BLUE BLUE
CON906
1 +12VA
VOL_LED7
2
VOL_LED6
3
VOL_LED5
4
VOL_LED4
5
VOL_LED3
6
VOL_LED2
7
8 VOL_LED1
VOL_LED8
9
TO LED BOARD
LG-MDT355
MIC/USB/KEY1/2/3/VFD
(2010. 06.14)
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