LG C1150 Service Manual page 72

Checking Flow
SETTING : After initialize Agilent 8960, Test EGSM, DCS mode
START
Check the signal level of
RCVP & RCVN at R408, R409. Are
these voltage is about 1.2V?
Yes
Check the signal level at R407. Is it
almost 0?
Yes
Check the contact state of dual
mode speaker.
The dual mode speaker will work
properly.
Waveform
U402. 4
U402. 5
C206
(REC-)
No No
Check the soldering
R408 & R409
Yes
Re-soldering
R408, R409
No
No
Check the soldering
of U402
Yes
Re-soldering U402
No
Replace the dual mode speaker
Graph 4-10
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4. TROUBLE SHOOTING
Replace the Main board.
ABB is out of order.
Replace U402
AC voltages of the
signals