4. TROUBLE SHOOTING
CIRCUIT
CHECKING FLOW
LGE Internal Use Only
LGE Internal Use Only
Key Backlight LED
VBAT
EDLH0013403
LEWWS47PAZ
LD200
LD201
D200
D201
R209
R210
DNI_VARISTER_1005
DNI_VARISTER_1005
20
20
3
Q200
2
KTC4075E
1
EQBN0007601
R212
100K
START
Is Pin3 of Q200 low
at KEY_BL_EN = high ?
YES
Are all LEDs
Working?
YES
Backlight will work properly.
- 100 -
R211
KEY_BL_EN
1.2K
NO
Check Q200
NO
Check the soldering
each R and LED
NO
Replace or resolder
component
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes