LG F1200 Service Manual page 50

Start
Earphone Receiving Problem
CW signal appear
at L502, L501?
YES
CW signal appear
at pin 4, 5 of
CN500?
YES
Change the Earphone
Start (MP3 mode)
Earphone Receiving Problem
MP3 signal appear
at C542, C543?
YES
Amplified MP3
signal (about 4 times) appear
at pin 4,5 of CN500?
YES
Change the Earphone
NO
Change the Main-PCB
NO
Soldering status of
C526, C527, R510, R511
is OK?
YES
Logic Level is Low at R519?
YES
Change the U505
NO
Change the
Main-PCB
NO
Soldering status of
C526, C527, R510, R511
is OK?
YES
Logic Level is High at R519?
YES
Change the U505
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4. TROUBLE SHOOTING
NO
Resolder C526,
C527, R510, R511
NO
Change the Main-PCB
NO
Resolder C526,
C527, R510, R511
NO
Change the Main-PCB