3-13
Copyright © 2019 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
H:2.55mm
R7A2
R7A3
R 7 B 0
R7B1
R 7 B 4
R7B9
R7C0
C7A2
C7A3
Z D
ZD7
0
ZD703
F R +
Q 7 0 8
Q 7 0 9
L709
L710
R30
R 3 0 1
R30
R 3 0 6
J K 5 0 2
R307
F L +
F L -
R328
R715
R716
R33
C302
R340
C 3 0 6
R E M O _ T P
C707
C708
C 7 3 1
C736
C737
R774
C 7 3 8
C 3 5 1
R 7 7 5
C 7 3 9
R 7 7 7
C741
R 7 8 2
R 7 8 3
R 7 8 4
R 7 8 5
C753
C754
C755
C756
IC703
ONE POINT REPAIR GUIDE
PROTECTION ERROR
No display or No Sound.
3-2. B(BURNT) PROTECTION
3-2-1. Solution
Replace MAIN board.
3-2-2. How to troubleshoot (Countermeasure)
1) Check voltage 12 V of IC703 at pin1 ~ 2, if 12V has problem refer to STEP 1-1.
2) If 12 V is OK, replace MAIN board.
3-2-3. Service hint (Any picture / Remark)
IC703
IC703
AMP_FAULT
C738
1uF
C736
100pF
R7A3
0
R782
100
C731
100nF
AMP_PROTECT
R775
47K
PGND
R783
NC
PGND
DC_PROTECTION
R702
27K
C739
1uF
PGND
R777
100
C730
1uF
R715
47K
R703
10K
ZD702
Z02W3.9V
NC
1
2
3
C706
100pF
VCC33
IC703
26
GND
1
GVDD_AB
11
GND
35
OUT_B
3
OC_ADJ
8
DVDD
6
INPUT_B
34
GND
27
OUT_D
33
GND
7
C_START
5
INPUT_A
30
PVDD_CD
9
GND
28
OUT_D
10
GND
29
PVDD_CD
4
/RESET
31
PVDD_CD
36
PVDD_AB
2
VDD
32
OUT_C
12
GND
25
GND
13
AVDD
14
INPUT_C
23
BST_D
24
BST_C
15
INPUT_D
22
GVDD_CD
16
/FAULT
21
M3
17
/OTW
18
/CLIP
19
M1
20
M2
37
PVDD_AB
38
PVDD_AB
39
OUT_A
40
OUT_A
41
GND
42
GND
43
BST_B
44
BST_A
R7A2
NC
ZD701
KDZ13V-RTK/P
NC
C741
10uF
AMP_PDN
C737
1uF
R774
3.3
+12V
C708
100pF
R716
4.7K
C707
100pF
R784
2.2K
ZD703
Z02W3.9V
1
2
3
FL_OUT_N
FL_OUT_P
FR_OUT_P
FR_OUT_N
FRONT L
FRONT R
< MAIN board bottom view >