LG C1100 Service Manual page 46

(2) Checking VCTCXO Circuit
Test Points
X301. 4
Figure 4-3.
Circuit Diagram
C373
100p
VVCXO
R314
100
C371
2.2u
(1608)
Waveform
Checking Flow
Check Pin 3.
Refer to Graph 2-1
Check Pin 4.
Refer to Graph 2-2
X301. 3
X301
3
OUT
4 2
VCC GND
13MHz
- 45 -
4. Trouble Shooting
Yes
13 MHzO.K?
No
Yes
2.75V OK?
No
Check U101, PMIC
R315
AFC
15K
C372
1000p
VCTCXO Circuit is OK
See next Page to check
ANT SW & Mobile SW
Changing X301
AD6535_AFCDAC