Huawei Y511-U030 Repair Manual page 40

XXXX The basic version Repair Manual
二. Phone does not boot repair analysis
1.
Press the power button does not boot:
First, remove the battery, power supply directly to the mobile phone with an external DC
power supply, press the power key according to the changes in the current mobile phone, specific
analysis:
Current does not change, it is likely that the boot key failure, should check the power button
contact is good.
The current will have the obvious change, but no boot instructions, such as the keyboard
light, power ring, we must first eliminate software does not boot, re download a software, can not
solve the problem, need to check whether the main chip, a power management chip, FLASH and
whether the weld and damage as possible.
High current hundreds of Ma, first check the welding parts such as PCBA; LCD connector,
speakers, keyboard FPC welding is good, there is no short circuit phenomenon, can not be ruled
out you need to press PCBA bad repair process
2. Insert the charger does not boot:
In the presence of a battery into the charger is no reaction, no charging indicator, first check
the battery contact is good, then there is no problem to further observe the output current charger
(using an external power supply with current indication for charger) size as the basis: if the
charger without output current, charging to check the USB connector on the motherboard the pin
is good contact, and then the charging management device can work normally, the last may
charge circuit is power management chip has been burnt, need to replace the chip.
3. Boot crash, automatic shutdown:
First check the external power supply is limiting, adjust to the appropriate position to test, if
the use of battery boot to confirm the battery power is sufficient, the normal is more than 3.7V can
boot stability. There is a boot ready to play on tone crash, general is horn welding when the
welding point and short circuit, and the LCD connector, MIC peripheral devices can also be
caused by bad welding welding boot crash, automatic shutdown, according to the bad check. If
you can't remove the fault, RF_PA may be damaged or other device is bad, need concrete
analysis on PCBA repair.
2013-09-25
V1.0
华为机密，未经许可不得扩散
internal public
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