Bluetooth Trouble - LG KF700Q Service Manual

4. TROUBLE SHOOTING

4.10 Bluetooth trouble

Bluetooth supplied voltages are generated by the PM6658.
Those signal's path are : PM6658
TCXO_BT 19.2MHz is asserted
control is operated (SBST / SBCK / SBDT)
BT_CLK BT_CLK
C182 C182
1u 1u
VREG_MSMP_2.7V VREG_MSMP_2.7V
C190 C190
100p 100p
VREG_TCXO_2.85V VREG_TCXO_2.85V
TCXO_PM TCXO_PM
TCXO_RTR TCXO_RTR
LGE Internal Use Only
→
VREG_MSMP_2.7V and VREG_BT_2.85V is asserted
→ →
Bluetooth ON
C175 C175 DNI DNI
1.8nH 1.8nH
L119 L119
NA NA
16 16
ANT ANT
C179 C179 1000p 1000p
9
CLK_REF CLK_REF
M101 M101
3
VCC_OUT VCC_OUT
LBRQ-2B43A LBRQ-2B43A
2
VDD_INT VDD_INT SYNC_DET_TX_EN SYNC_DET_TX_EN
10 10
VDD_MSM VDD_MSM RX_BB_TX_BB RX_BB_TX_BB
C183 C183
1u 1u
14 14
VDD_BAT VDD_BAT
20 20 19 19 18 18 17 17
C191 C191 C192 C192 C193 C193
0.1u 0.1u 2.2u 2.2u 100p 100p
smd_1608h_9_r smd_1608h_9_r
X101 X101
DSA321SCE-19.2M DSA321SCE-19.2M
4
VCC VCC VCONT VCONT
3
C161 C161 C162 C162
OUTPUT OUTPUT
0.1u 0.1u 0.01u 0.01u
8
NC4 NC4
7
NC3 NC3
C167 C167
1000p 1000p
C168 C168
1000p 1000p
[Fig. 4.11] Schematic of Bluetooth Interface
- 100 -
→
BT_TX_RX_N is High
BT101 BT101
NC1 NC1
FEED FEED NC2 NC2
C176 C176
4
SBST SBST BT_SBST BT_SBST
11 11
SBCK SBCK BT_SBCK BT_SBCK
12 12
SBDT SBDT
5
BT_TX_RX_N BT_TX_RX_N
R115 R115
0
13 13
C184 C184
7 1000p 1000p
XTAL_IN XTAL_IN TCXO_BT_PM TCXO_BT_PM
15 15 8 6 1
VREG_BT_2.85V VREG_BT_2.85V
R112 R112
1
100ohm 100ohm
2
GND GND C163 C163
0.01u 0.01u
5
NC1 NC1
6
NC2 NC2
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
→
BT serial interface
BT_SBDT BT_SBDT
BT_DATA BT_DATA
TRK_LO_ADJ TRK_LO_ADJ