LG GD330 - Slide LCD Backlight LED Trouble Shooting

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Only for training and service purposes
4. TROUBLE SHOOTING
4.19. Slide LCD Backlight LED Trouble Shooting
z Slide LCD backlight LED Operation scheme is shown below.
z Slide LCD Backlight operation
- Slide backlight LED is controlled with MLED_C1~5 and Navi_LED_1 signals
- Main Flexible FPCB
- LCD_BL_CTRL signals from DBB(U101)
- The LEDs are forward biased and turned on
z Check Point
- VBAT level ( 3.35 ~4.2V)
–Main FPCB
-LEDs
- Charge pump
u1
2
06C
81
6C
u1
206
R
K0
0
1
p
72
60
6
C
T
ABV
90
6C
p
72
106C
u
1
0
0
6
AV
306C
u2
.
2
40
6C
p72
?
A
V
SEVY0003801
7
0
6
C
p72
1
6D
2
3
T
E
S
_
NE
D
N
G
0
1
NI
9
6
PC
T
U
O
5
1
DN
G
P
1
T
-
O
FI
9
613T
A
A
0
0
6
U
4
+1C
-1C
5
7
+
2
C
8
-2
C
1D
1
1
2
D
2
1
3
D
3
1
4D
41
5D
p7
2
806
C
5
0
6C
p
72
0
06
C
u1
A
_D
E
L
M
C
_DEL
_
I
VA
N
1C
_
DEL
M
2
C_D
E
LM
3
C
_DE
LM
4C_D
EL
M
5
C
_
D
E
L
M
L
R
TC
_
L
B
_
D
CL