LG GX300 Service Manual page 93

4. TROUBLE SHOOTING
CHECKING FLOW
CN501 with LCD connector ok ?
CN501 with CN100 connector ok ?
Check the Voltage Level of
TP1 is about Battery voltage ?
Check the Waveform of
EMI filter( TP3, TP4, TP5) ?
LGE Internal Use Only
START
Is the connection of
YES
Is the connection of
YES
(LCD_BL_EN signal
is high Level)
YES
YES
Check the Waveform of
Data pins on CN100 ?
YES
Does LCD work
properly ?
YES
LCD working well !
4. TROUBLE SHOOTING
NO
Reassemble LCD connector
NO
Reassemble FPCB
with Main connector
NO
Resoldering or Replace U500
NO
Resoldering EMI filter.
(FL500,FL501,FL502)
NO
Replace Main FPCB
NO
Replace LCD module
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