LG F3000 - Page 59

(1) Checking VCTCXO Circuit
4. TROUBLESHOOTING
- 60 -
Check Pin 3.
Refer to Graph 4-1(b)
26 MHzO.K?
No
VCTCXO Circuit is OK
See next Page to check
ANT SW & Mobile SW
VCTCXO Circuit is OK
See next Page to check
ANT SW & Mobile SW
Yes
Check Pin 4.
Refer to Graph 4
-1(a)
2.75V OK?
No
Yes
Changing X500
Check U101
(1608)
10KR510
0R746
2.2u
C528
3
OUT
4
VCC
1
VCONT
26MHz
X500
2
GND
C529
1000p
2V75_VVCXO
AFC
TEST POINT
CIRCUIT
Waveform
Checking Flow
Graph 4-6(a)
Graph 4-6(b)