Huawei YU220, Service Manual

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YU220 service manualV1.0
2013-10-18
Huawei secrets, no dispersion without permission

Failure analysis process:
Fault 1: Insert the headset, silent, unable to detect headphones plugged;
Repair process: First, replace with a new headset first to see if the recovery
exclusion headphone monomer problem, if not the headphones monomer
confirm the problem, then the headset is plugged into, whether measured
EINT_HP signal is pulled low, not pulled low and then sequentially
detects R805 whether Weld, B804 bead inductors are Weld, headphone
socket is soldered, the headset is bad;
Fault 2
:
always show headset is plugged
,
unplug the headset cannot be detected
;
Repair process: first rule headset monomer problem, if not the headphones own fault,
then plug in your headphones and then pull out after the first measurement
EINT_HP whether the signal has been low, if the test has been low, respectively,B801,
B802, short circuit (may be sequentially removed B801, B802 look headset unplugged,
EINT_HP signal is set high)