LG KP175 - Page 41

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
- 42 -
(1) Checking Crystal Circuit
R706
X500
26 MHzO.K?
No
Crystal Circuit is OK
See next Page to check
Mobile SWe
Yes
Change X500
0R706
R514
10K
0.1u
C512
2V75_VVCXO
VCC_REF
VAFC_NC
18
VCC_BBQ
24 17 23
Q
QB
22
REFIN
20 19
REFINB
21
REF_OP
C513
0.1u
AFC
TEST POINT CHECKING FLOW
CIRCUIT
WAVEFORM
Graph 4.2.1(a)
Graph 4.2.1(b)