LG GX500 - LCD LED Trouble

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4. TROUBLE SHOOTING
GX500 Operational Description Revision A
LG Electronics 93/143 LGE Property
4.11 LCD LED trouble
Check Points
-Signal path is connected well
Figure 4-27. LCD BACKLIGHT LED DRIVER Circuit
Checking Flow
START
Check TP1 is
hl
g
h ?
Check TP2 is
hi
g
h?
Assemble
Check R224 and
Replace
Check and Replace
charge pump.
(U205)
Yes
No
No
Check All of LEDs solder
Yes
TP1
TP2
VA205
EVLC18S02015
VA203
AAT3369IDT-1-T1U205
19
5
15
14
13
7
6
17
4
3
2
18
98
16
10
11
1
12
D3
OUTCP1
D2
D1
EN_SET
PWM FCAP
OUTCP2
C1-
C1+
C2-
C2+
IN
GND
D4
D5
D6
NC
EP
C253
1u
VBAT
10K
R224
47n
C256
0
522R
C255
1u
1uC252
C254 1u
LCD_BL_CTRL
MLED5
MLED4
MLED3
MLED
MLED2
MLED1
MLED6
LCD_PWM
LCD BACKLIGHT LED DRIVER
TP1
TP2