LG KE800 Service Manual page 62

4.18.3 Headset Trouble
2V65_ANA
HOOK_DETECT
R407
1.5K
R409
MIC2_N
C403 0.1u
MIC2_P
C404 0.1u
MULTI_PORT_2
C412
C410 C411 MULTI_PORT_3
27p 27p MULTI_PORT_0
10u
MULTI_PORT_1
JACK_DETECT
Check
Audio signal from Mic. is
OK (C404)
Check
JACK_DETECT is "Low"
(VA401)
Check
HOOK_DETECT is "Low"
When Send/End is pushed
(R402)
18PIN MUILTIPORT RECEPTACEL
2V85_IO2
U401
LMV7291MGX-NOPB
5
4 VIN-
R402
1 VCC
OUT 3 VIN+
GND
0
C401 2
100p
2.2K
JACK_TYPE
R411 33
R412 33
R414 1K
RPWRON
R446 NA
DSR
TX_DEBUG
RX_DEBUG
C415 C416
39p 39p
FM_ANT
2V65_ANA
VBUS_USB 2V72_IO
R401
1M
R408
220K
C402 27p
L401 100nH
FB405
R416 47
C413 C414
VA401
100p 4.7u
Check
Mic. Bias(R409)
Check
Stereo output(C425,C426)
Check
JACK_TYPE is "Low"(VA409)
When Ear-jack is plugged-in
When no sound from ear-piece(R427)
- 63 -
4. Trouble Shooting
2V72_IO VCHG VBAT
CN401
21
19
1
FB408 2
3
4
FB403
5
FB404
6
FB409
FB410 7
FB411 8
9
10
11
12
13
14
15
16
R417 47 17
18
20
22
VA402
R442
C420 R443
L402
27p
0
100nH 0
As close as possible to the connector
Check
DIF_VSYNC is "Low"