LG C1100 Service Manual page 80

Earphone detect problem
Voltage at R150
= 2.8V ?
5
Voltage at Pin 3
of U104> Voltage at Pin 4
of U104?
Resolder or replace U104.
Earphone sending path problem
Earphone sending
path problem
3
Voltage at A point
= 1.5~1.9 VDC ?
Yes
Is the signal level
across C166&7a few tens
or hundreds
VAC ?
Yes
Resolder C166&7.
Yes
1
Earphone detect
problem
No
Yes
No
Yes
4
No
Resolder
R153, R159.
No
Resolder R181.
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Voltage at Pin1 of
U104 = 2.8V ?
Yes
Resolder R150.
Resolder R145, R147, R144
No
Does it work well? Redownload software.
Does it work well?
Yes
4. Trouble Shooting
No
5
No
Change the main board.
Yes
4