LG C3400 Service Manual page 59

4. Troubleshooting
(2) Checking VCTCXO Circuit
TEST POINT
X500. 3
Figure 4-3
CIRCUIT
Waveform
Check Pin 3.
X500. 4
Refer to Graph 4-1(b)
Check Pin 4.
Refer to Graph 4-2(a)
Graph 4-1(a)
Checking Flow
26 MHzO.K?
No
2.75V OK?
No
Check U101, PMIC
- 58 -
VCTCXO Circuit is OK
Yes
See next Page to check
ANT SW & Mobile SW
Yes
Changing X500
Graph 4-1(b)