4. TROUBLE SHOOTING
- 49 -
(1) Checking Regulator Circuit
U503. 3
U503. 5
Figure 4-2
(1608)
(1608)
RF_LDO
VBAT
RF2.85V
C536
C529
4.7u
4.7u
U503
BYP
4
3
EN
2
GND
IN
1
OUT
5
MIC5255-2.85BM5
C535
22n
CLKON
Regulator Circuit is OK
See next Page to check
VCTCXO
Voltage at
Pin5 of U503
Is 2.85V?
Level at
Pin3 of U503
Is high?
YES
NO
Replace U503
YES
NO
Change main board
Test Points
Circuit Diagram
Checking Flow
Summary of Contents for C2100
Page 1: ...Service Manual Model C2100 Service Manual C2100 P N MMBD0048201 Date April 2005 Issue 1 0 ...
Page 76: ...4 TROUBLE SHOOTING 77 4 10 KEY backlight Trouble Test Points Figure 4 21 ...
Page 104: ... 105 8 PCB LAYOUT ...
Page 105: ... 106 8 PCB LAYOUT ...
Page 113: ...10 STAND ALONE TEST 114 Figure 10 2 HW test setting Figure 10 3 Ramping profile ...
Page 117: ...Note 118 ...
Page 119: ......
Page 135: ......