4. TROUBLE SHOOTING
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Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4.8.2 Checking Crystal Circuit
System Setting -> Location Service -> GPS satellites Check -> Enter test mode *#*#880#*#* -> GPS Test ->
Positioning Test -> Setting Key ‘Start GPS’
If Setting is right, mobile should display and blink GPS icon
Positioning Test
Setting Key ‘Start GPS’
If Setting is right, mobile should display and blink GPS icon
GPS TCXO
Circuit
26M_TCXO_IN
Vpp1.16V@26MHz
Test Point
26M _TCXO_IN
Vpp 1.1V @ 26MHz
Check
Flow
26M_TCXO_IN OK?
Replace X1200
X12000 OK
See Next Page
26M _TCXO_IN
Vpp 1.1V @ 26MHz
4.4 Checking GPS LDO
System Setting
Location Service
GPS satellites Check
Enter test mode *#*#880#*#*
GPS Test
TP1 (26M_TCXO_IN) OK?
Replace X1200
X12000 OK See Next Page
TP1(26M _TCXO_INVpp 1.1V@ 26MHz)
26MHz
3
2
4
1
X1200
0
1XXB26000CA
C
GND1
VC
C
GND2
OU
T
0
R12001
1u
C12011
VDD_GPS_TCXO
VDD_GPS_TCXO
FB12000
C12006
2.2u
22p
C12004
2.2u
C12005
VDD_TCXO_OUT
A1
VDD_GNSS_1V2_I
D1
XO_OUT
D3
TCXO_IN
E3
TP1 26M _TCXO_IN
Vpp 1.1V @ 26MHz