Keypad Backlight Trouble - LG GW520 Service Manual

5. Trouble shooting

5.8 Keypad backlight Trouble

Checking Flow Checking Flow
Start Start
Check soldering of Check soldering of
LD400~LD403, R439 LD400~LD403, R439
R442, R444, R445 R442, R444, R445
YES YES
Is the level of Is the level of
QWERTY_KEY_BL low? QWERTY_KEY_BL low?
Check TP1 Check TP1
YES YES
Is signal QWERTY_KEY_EN Is signal QWERTY_KEY_EN
Low? Low?
Check TP2 Check TP2
YES YES
Does backlight work well? Does backlight work well?
YES YES
END END
Circuit Diagram Circuit Diagram
VBAT
EDLH0013701
LD400
LEWWS44-E
LD401
LEWWS44-E
LD402
LEWWS44-E
LD403
LEWWS44-E
LGE Internal Use Only
NO NO
Resolder LD400~LD403, Resolder LD400~LD403,
R439, R442, R444, R445 R439, R442, R444, R445
NO NO
Change the Main Board Change the Main Board
NO NO
Change LD400~LD403 Change LD400~LD403
And check again. And check again.
Work well? Work well?
R439 47
R442 47
R444 47
R445 47
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GW520 service manual
NO NO
Change the Main Board Change the Main Board
YES YES
QWERTY_KEY_BL
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