LG KG290 - Page 62

LGE Internal Use Only Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
- 63 -
(1) Checking Crystal Circuit
X500
R520
C547
26 MHzO.K?
NoNo
Crystal Circuit is OK
See next Page to check
Mobile SW
See next Page to check
Mobile SW
Yes
Change X500
1M
R520
C543
1000p
2V75_VVCXO
42
3
GND
VCC
5
U502
2.2u
C547
26M_DBB
TEST POINT CHECKING FLOW
CIRCUIT
WAVEFORM
Graph 4.3.1(a)
Graph 4.3.1(b)