LG VX5400 Service Manual page 99

SETTING : "Melody on" at sounds of test menu.
START
Voltage across C423
Is over 3.4~4.2V
YES
Check the sgnal level of
PIN BYPASS of U403
YES
Check the soldering of PIN
STANDBY of U403
YES
Check the signal level of
PIN Vout 1,2 of U403
YES
Check the state of contact
Of speaker
YES
Speaker will work properly
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Only for training and serving purposes
NO
Check the soldering of PIN
Vcc of U403
NO
YES
NO
Check the soldering of R438
NO
Resoldering contact of
speaker pad on LCD module
Checking Flow
Checking Flow
YES
Resoldering U403
Check the soldering of PIN
Vcc of C424
YES
Resoldering U403
YES
Resoldering R438
-99-
NO Change Main Board
Internal Pattern is
opened
NO
Replace MSM
NO
Replace MSM
Replace U403
LGE Internal Use Only