Earphone Trouble - LG CE500 Service Manual

4. TROUBLE SHOOTING

4.11 Earphone Trouble

Test Point
U201
R206
R212
Circuit Diagram
STEREO HEADSET INTERFACE
2V8_VMEM 2V5_VMIC 2V8_VMEM
U202
B0 A
4
GND VCC
5
B1 S
6
FSA4157L6X
C202
39p
R207 100
AUX_MICP
AUX_MICN
R201 100
C201 0.1u
R210
R211
C212
U202
C211
R207
VMEM → VMIC Switching
When circuit call is activated.
3
2
VMIC_ON MIDI_HEADSET_EN
1
R209
C205
0.1u 100K
R217
100K
C204
EAR_PRECHARGE
10u
R215
R205
39K
2K
CARKIT_MICP
R204
C203
2K
39p
R213
R202
27K
NA
- 56 -
J201
Removing DC noise circuit, when
audio path is opened.
This signal comes from DBB, and
when ear-jack was detected, this
circuit is worked.
EARPHONE & HOOK DETECT INTERFACE
JACK_DETECT
HOOK_DETECT
U203 FSA2267L10X
2V8_VMEM
2A 2B1 HSO_L
6 4
2S 2B0 HEADSET_L
7 3
R208
1S 1B1 HSO_R
8 2 1M
1A 1B0 HEADSET_R
9 1
5
VIN- 4
2V8_VMEM VCC
VIN+ 3 OUT
GND
U201
2
LMV7291MGX-NOPB
R203
330K
C280
0.01u
CARKIT_MICP
R216
39K
R211 10
C211 100u
R210 10
C212 100u
R214
C206
27K C207 C216 C213
39p 39p 39p
27p
Ear-jack
STATUS HIGH LOW
Not Inserted Inserted
Pressed Not Pressed
1
HOOK_DETECT
R212 100
JACK_DETECT
C210 C208
100p 100p
J201
C215
27p