LG -A100 Service Manual page 59

(1) Checking Crystal Circuit
TEST POINT
TP1 (X101 1pin)
CIRCUIT
A9
FMRIN
A8
FMRINX
F1
XO
F2
XOX
A4
RX12
A3
RX12X
A6
RX34
A5
RX34X
B1
TX1
B2
TX2
A2
FE1
C1
FE2
D2
PABS
E3
LGE Internal Use Only
TSX-3225 X101
4
3
HOT2 GND2
2 1
GND1 HOT1
26MHz
RF_LB_RXP
RF_LB_RXN
RF_HB_RXP
RF_HB_RXN
RF_LB_TX
RF_HB_TX
TP1
RF_VLOGIC
RF_2G_BS
CHECKING FLOW
TP1(26 MHz)
OK?
Yes
Crystal is OK.
See next page to check PLL Circuit
WAVEFORM
TP1
TP1
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4. TROUBLE SHOOTING
No
Replace X101
Only for training and service purposes