Huawei u8800 - No Power On-Small Current

U8800 Maintenance Manual Basic Version V1.1 Internal
2011-03-21
Huawei confidential. No spreading without permission. Page 34 of 61
9.2.2 No Power on--Small current
Analysis：The current is among 10mA-500mA scope as power supply by DC-power. The problem of software or
FLASH causes the failure usually. Reference Figure 9-2
J1501 Pin3-VBAT
3.7-
4.2V
J1102
Pin1-test
LB1101
5.0V
Figure9-1
U3302
VBAT-test
C3302
3.7-
4.2V
U3501
VBAT-test
C3501
3.7-
4.2V
U1001
VPH_PWR-test
L1001
3.7V
U201
U3302
U3501
U3402
U1001 CHG_CHIP /
J
11
0
2
U3402
VCC-test
C3406
3.7-
4.2V
U301
U301
VPH_PWR-test
C409
3.7V
Q301 MOSFET /