LG KF350 Service Manual page 88

4.13.1. Checking DCXO Circuit
Checking Points
X400
TP1(C439) : 26MHz
Figur2. DCXO
DCXO Circuit Diagram
16
VDDXO2V8
15
FSYS1
14
GND1
13
X400 NX3225SA
4
3
GND2 HOT2
1 GND1 2
HOT1
26MHz
Figure 3. DCXO Cicuit
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Only for training and service purposes
Checking Flow
Is the waveform
of TP1(C439) similar to Fig.6?
Yes
DCXO Circuit is OK.
See next page to check
PLL Circuit.
Waveform
C439
26MHZ_MCLK
1000p
Figure 4. DCXO Waveform
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4. TROUBLE SHOOTING
No
Replace X400
TP1 (C439)
LGE Internal Use Only