LG KD3500 Service Manual page 46

Earphone receiving path problem
2
Is level detected
form R332, C307, & L305?
Yes
No
Check soldering of
Pin 2 of CON301
Yes
Change QSC, or
main board
Earphone sending path problem
path problem
3
Check R333
OK
No
Does it work well?
Yes
Yes
4
Replace them, or re-download SW
Re-solder or Replace
CON301
Earphone
sending
NG
Re-solder or replace it
Re-download
software
Does it work well?
No
Change main
board