LG KM380t Service Manual page 84

6.12.3 DCXO circuit
TP
√ The output voltage of X100 is 890mV
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Only for training and service purposes
DCXO Circuit
Is the waveform of
TP(X100) similar to Fig6?
YES
DCXO is OK.
See next part.
Fig 4 Debugging flowchart of DCXO circuit
X100 26MHz
4
HOT2 3
GND2
1 HOT1 2
GND1
NX3225SA
p-p.
- 85 -
6. Trouble shooting
NO
Replace X100
SIM_IO
SIM_CLK
SIM_RST
Fig 5 DCXO circuit (X100)
Fig 6 Waveform of DCXO
U4
REFR
W7
XOX
W8
XO
V10
CC_IO
U9
CC_CLK
V9
CC_RST
U10
LGE Internal Use Only