Huawei YU220 Service Manual page 45

YU220 service manualV1.0
Camera ： including power, clock, USB cable and control line, power line
include VCAMA_PMU （2.8） 、VCAMD_PMU （1.8） 、VCAMD_IO_PMU （1.8） . clock
link include CMMCLK，CMPCLK， DATA，RST，SDA，SCL。
Detection flow：
General phone camera without image, there are four possibilities: firstly
get rid of LCD failures. 1. Camera bad; 2, camera and the socket bad contact; 3,
connector dry joint. 4, CPU chip U301 exception. So first determine whether
there is power cord, if the power cord abnormalities, first determine whether a
short circuit, short circuit, please remove the appropriate path if the
capacitance, if not short-circuit the plus welding PMU circuit; look at whether
there is a clock signal output without output, you can first add welding CPU
chip; see if there is signal signal line, if not, then the CPU exception, can be
welded CPU retest. If the external signal has, then we can conclude that the
connector is bad, can be welded in the test
.
Huawei secrets, no dispersion without permission
2013-10-18