LG KG920 - Page 97

4. TROUBLE SHOOTING
- 98 -
KEY BACKLIGHT
390
R105
LD110
LEBB-S14H
LD113
LEBB-S14H
LD106
LEBB-S14H
4.7K
R123
390
R112
LD101
LEBB-S14H
390
R118
390
R117
LD107
LEBB-S14H
LD104
LD118
LEBB-S14H
LEBB-S14H
LD117
LEBB-S14H
390
R110
390
R116
LEBB-S14H
LD109
R108
390
R107
390
LD111 LD115
LEBB-S14H LEBB-S14H
LD103
LEBB-S14H
LD116
LEBB-S14H
R122
4.7K
LEBB-S14H
LD114
LEBB-S14H
LD102
Q101
UMT2222A
390
R113R111
390
390
R103
390
R121
LD108 LD105
LEBB-S14H
R115
390
LEBB-S14H
390
R114 R120
390
R109 R119
390
LEBB-S14H
390
LD112
R104
390
VBAT
390
R106
LEBB-S14H
LD119
KEY_BACKLIGHT
CIRCUIT
START
Is the level at R122
High?
NO
Check U101(Main board)
YES
Are all LEDs
Working?
NO
YES
Check the soldering
each R and LED
Backlight will work properly.
NO
Replace or resoldering
component
R103~R121
LD101~LD119
CHECKING FLOW
Figure 4-40.
Figure 4-41.