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G700-U10 Smartphone
Maintenance Manual
10 Circuit and Failure Analysis
Issue 1.0 (2013-07-22)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
60
Troubleshooting Process
Figure 10-32
Troubleshooting front camera failures
Front camera failure
Is the front camera
normal?
Replace the rear camera module
Y
Is the front camera BTB
connector normal?
Resolder or replace the BTB
connector
Y
N
N
Replace U401
Is the power supply to the
front camera normal?
Check the three power supplies near
J1001 and then check U202
N
Y
Is the MIPI signal
normal?
Resolder or replace T1001, T1002,
T1003, T1004, or T1005
N
Y
Y
Circuit Signals
Table 10-7
Circuit signals of this section
Signal
Description
Reference Value or
Waveform
VCAM_AVDD
Camera analog power supply
2.8 V
VCAM_DOVDD
Camera digital power supply
1.8 V
SUBCAM_PDN
Camera power supply enabling signal
Effective when at high
level (operating)
SUBCAM_RST
Camera initialization signal
Effective when at low
level
The operating level is
high.
CMMCLK
Reference clock for the camera; 24
MHz
Digital pulse signal
SUBCAM_CLKN/P Pixel clock for the system
MIPI differential clock
SCL1
Camera I2C signal for transmitting
control and configuration data
Digital pulse signal
SDA1
Digital pulse signal
SUBCAM_D0N/P
MIPI differential data signal
Differential data signal