(1) Checking Regulator Circuit
TEST POINT
CIRCUIT
CLKON
Checking Flow
Voltage at
Pin5 of U503
Is 2.85V?
YES
Regulator Circuit is OK
See next Page to check
VCTCXO
U503. 5
(OUT)
U503
VBAT
R522
0
C545
R523
100K
1u
Level at
NO
Pin3 of U503
Is high?
YES
Replace U503
- 39 -
4. TROUBLE SHOOTING
U503. 3
(EN)
RF2V85
U503
MIC5255-2.85BM5
1
5
IN
OUT
2
GND
3
4
EN
BYP
C546
C547
0.01u
4.7u
NO
Change main board