LG U8290 Service Manual page 137

4. TROUBLE SHOOTING
MP3 play for Head_Set
FB502 FB503
39p 39p
C621 C622
and in sert the Head_set
Can y ou he ar the tone ?
MICBIAS_LDO_1.8V
VREG_MSMP_2.6V
MIC2P
MIC2N
HEADPHONE_L
HEADPHONE_R
EAR_SENSE*
MULTI_ADC
KEY_ROW(0)
KEY_ROW(1)
KEY_ROW(2)
KEY_ROW(3)
KEY_COL(6)
Near to MSM
Start
Play t he MP3
The MP3 wave ap pear at
C626,C627?
YES
YES
END
EAR JACK
10K R625
22n C102
C115
22n
33u C626
33u C627
0 R624
VA8
C654 C653
39p 39p
AVLC14S02050
D503
NO
Check R624 is 0V? or
Change the Main boa rd
NO
Change the Head_Set
- 138 -
To prevent from
CN304
13
TDMA noise.
15
1
R640 600
2
R641 600 3
4
5
6
7
8
9
10
11
12
14
16
D599