3-7
Copyright © 2019 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR “HELLO”
ON FRONT PANEL
When you turn on your set, it will blank / no message on front panel, LCD doesn’t work.
1-3. LCD System power VCC_5V
1-3-1. Solution
Replace MAIN/ FRONT board.
1-3-2. How to troubleshoot (Countermeasure)
1) Please check CN107 VCC_5V of CN107 pin1.
2) If VCC_5 V is abnormal, replace MAIN board.
3) If VCC_5 V OK, replace LCD module.
1-3-3. Service hint (Any picture / Remark)
< MAIN board top view >
R1D1
R1D2
R1D3
R 1 D 4
R1F4
R1H8
Q 1 0 1
TP149
49
TP151
TP152
TP153
TP154
TP155
TP156
TP157
TP158
TP160
M3
R1M9
FB101
FB111
R 1 0 2
R 1 0 3
R
R 1 0 6
R 1 0 7
R 1 0 8
R 1 1 1
R 1 1 2
R 1 1 3
R114
R115
R117
R120
CN106
C N 1 0 7
8
C105
R 1 4 7 R 1 4 8
C 1 1 4
C 1 1 5
R 1 5 2 R 1 5 3
C 1 2 0
C 1 2 1
C122
R160
R 1 6 1
R162
R 1 6 3
R164
R 1 6 5
R 1 6 6
R 1 7 3
R 3 8 0
C 1 6 4
K E Y
C 1 6 5
D111
D112
C178
C
I C 1 0 0
R201
R
2
1
3
DGND
TP123
3.3VA
C177
2.2uF
R201
10M
LCD_DAT
C178
0.33uF
DGND
R165
220
R166
220
LCD_CS
VCC_5V
LCD_CLK
FB111
PZ1608(220)
LCD_RST
C165
10uF
LCD_CD
C164
100nF
TP126
TP204
TP125
TP129
TP127
TP131
C117
2.2uF
DGND
LCD_BL
Q101
KRC103S
E
C
B
TP147
R161
0 NC
R164
0 NC
R163
0 NC
R162
0 NC
R160
0 NC
C166
10nF
TP202
TP124
CN107
04-6214-014-000-800
EAG30500902
0.5MM, STRAIGHT
1
LED+(A)
2
LED-(K)
3
CSB
4
RSTB
5
CD
6
SCK
7
SDA
8
VDD
9
VSS
10
VB0-
11
VB1-
12
VB1+
13
VB0+
14
VLCD
TP203
TP146
TP128
TP132
MICOM
TO LCD
VCC_5V
VCC_5V