Speaker Phone Path - LG L705i Service Manual

4. TROUBLE SHOOTING

4.16 Speaker phone path

MSM6280 HPH_L → Audio AMP → connector → Speaker
Connect the phone to network
equipment and setup call
Setup 1KHz tone out
Sine wave appears at
Connecting speaker OK?
Can you hear the tone?
Audio AMP
R304 C315 22n
R305
HPH_L
1K
C319 22n
R306
8200p
C318
SPK_AMP_EN
LOW: SHDN
LGE Internal Use Only
Start
R308 and R309
YES
YES
END
TPA2005D1ZQYR FB300
HB-1M1005-600JT
51K
D1 B4
IN- VDD1
C4
VDD2
B1
NC
51K
C1
U300
IN+
A4
VO-
A1 D4
_SD VO+
- 114 -
NO
Check R308/R309 or
Change the Main board
NO
Re-connect speaker
NO
Change the speaker
SELECT_SPK&RCV
C314
0.1u
RCV_EN: 0 --> NC, 1 --> NO
+VPWR
SPK_RCV+
R309 10
SPK_RCV-
RCV+
SPK_RCV+
TP310
RCV_EN
R309
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
R308
U301
NLAS5223BMNR2G
1 10
SPK_RCV-
VCC NO2
R308 10
2 9
NO1 COM2 RCV-
3 8
COM1 IN2
4 7
IN1 NC2
5 6
NC1 GND