Only For Training And Service Purposes - LG KG290 Service Manual

CHECKING FLOW
START
Resolder CN300
Does the audio
profile of the phone
change to the
earphone mode?
YES
Set the audio part of the test
Equipment to echo mode
Can you hear your
voice from
the earphone?
YES
Earphone will work properly
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Only for training and service purposes

NO
Level at pin3
of U302 is high
YES
Change the earphone
and try again
NO
Can you hear your
voice from
the earphone?
YES
Change earphone
YES
- 85 -
4. TROUBLE SHOOTING
NO
Replace U302
Resolder component
Set the audio part of
the test equipment to
PRBS or continuous
wave mode
NO
Can you hear
the sound from
the earphone?
YES
Download software.
Does it work well?
NO
If not, check the U300, U301
Change the main board.
Download software
NO
Voltage at
U301.5 is
High ?
YES
Voltage at
U300.1 is
Low ?
YES
Earphone will work properly
NO
LGE Internal Use Only