LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
5. Trouble shooting
- 96 -
5.14.1 Checking DCXO Circuit
TP1(C638) : 26MHz
X600
Replace X600
No
Yes
DCXO Circuit is OK.
See next page to check
PLL Circuit.
Is the waveform
of TP1(C638) similar to Fig.4?
TP1 (C638)
Figure 4. DCXO Waveform
Figure2. DCXO
2
GND1
GND2
4
1 HOT1
HOT2 3
26MHz
X600
TSX- 3225
p
0
0
0
1
8
3
6
C
0
4
6
C
n
7
4
0
2
8
7
0
6
R
VRF_2V85
7
1
8
V
2
O
C
V
D
D
V
8
V
2
O
X
D
D
V
5
1
X
O
1
1
1
2
X
O
X
C
R
_
O
C
V
8
1
8
V
D
D
D
IG
1
V
5
C
L
K
7
6
D
A
6
1
N
E
4
1
1
S
Y
S
F
1
0
F
S
Y
S
2
F
SY
S
3
9
3
1
1
D
N
G
PMB6272
U601
EUSY0274801
T
B
M
6
2
N
E
_
F
R
K
L
C
M
_
Z
H
M
6
2
TP1
Figure 3. DCXO Cicuit
Waveform
DCXO Circuit Diagram
Checking Points
Checking Flow
