(1) Checking Regulator Circuit
4. TROUBLE SHOOTING
- 62 -
U503.3
U503.5
U503
RF_LDO
(1608)
(1608)
RF2.85V
VBAT
C536
4.7u
4.7u
C537
4
BYP
EN
3
GND
2
1
IN
5
OUT
22n
C535
U503
MIC5255-2.85BM5
CLKON
Regulator Circuit is OK
See next Page to check
VCTCXO
Voltage at
Pin5 of U503
Is 2.8V?
Level at
Pin3 of U503
Is high?
YES
NO
Replace U503
YES
NO
Change main board
Test Points
Circuit Diagram
Checking Flow
Figure 4-2
Содержание C3380
Страница 1: ...Service Manual Model C3380 Date November 2005 Issue 1 0 Service Manual C3380 ...
Страница 3: ... 4 ...
Страница 83: ...4 TROUBLE SHOOTING 84 4 11 KEY backlight Trouble Test Points Figure 4 22 ...
Страница 98: ...4 TROUBLE SHOOTING 99 Yes No Yes No Replace M201 Establish a call Replace U101 Software Re_download ...
Страница 109: ...Note 110 ...
Страница 116: ... 117 8 PCB LAYOUT ...
Страница 117: ... 118 8 PCB LAYOUT ...
Страница 125: ...10 STAND ALONE TEST 126 Figure 10 2 HW test setting Figure 10 3 Ramping profile ...
Страница 129: ... 130 ...
Страница 131: ... 132 ...