Only For Training And Service Purposes - LG GT500 Service Manual

4.13.2 GPS Clock path
4.13.2 GPS Clock path
1
TP2
TP3
Sub PCB
X750 KT2520F16369ACW18T
1 6
GND1 VCC
2 5
NC1 NC2
3 4
GND2 OUT
C750
2.2u
VDDE_1V8
GPS Clock Buffer
ACC_GP_GPS_PON
MCLKSEC
TP3
2
Main PCB (Bottom side)
Copyright © 2009 LG Electronics. Inc. All right reserved.

Only for training and service purposes

TP1
R757
0
TP1
C751
0.1u
VDDE_1V8
R752
10
U750
NL17SZ126XV5T2G
C753 C754
OE VCC 0.1u 2.2u
A
R753
GND Y
33
TP4
th
(4 pin from the end
of the connector)
start
1
1. Check TCXO output
TP1: 16.369MHz
No
Yes
2. Check Buffered MCLKSEC
TP2: 26MHz
No
Yes
Go to 4.11.3
TP3: 26MHz
NG
4. Check
Mainboard Connector
TP4: 26MHz
GPS_CNTIN
NG
Check RF3300
TP2
24
25
26
27
28
29
30
G3 G4
- 117 -
4. TROUBLE SHOOTING
Replace X750
3. Check
MCLKSEC
OK
Replace U750
2
OK
Replace Sub
PCB
(U111)
TP4
37
36
FM_ANT
35
34
MCLKSEC
33
32
RTCCLK
31
LGE Internal Use Only