Model X771
L3 Service Manual
IV.
Ensure all components, modules, screws, and insulators are correctly re-fitted after servicing and
alignment
V.
Ensure all cables and wires are repositioned correctly if Handset disassembled
VI.
Electrostatic discharge can easily damage the sensitive components of electronic products. Therefore,
Service Centre must adhere the precautions which mentioned above.
Basic Structure of the Mobile Phone
PCBA Diagrams of A81 Mainboard
J400 earphone connector
Failure caused by damage:
Earphone failure, FM failure
J100 antenna bonding pad
Failure caused by damage:
Weak BT signal
J800/J802 SIM1/SIM2 card
socket
Failure caused by damage:
Failure to identify GSM/
U600 charge IC
Failure caused by damage:
Failure to No indication during
charging
ANT1/ANT2
GSM
PAD
Failure
caused
by
damage: GSM failure
U0101 GSM PA chip Failure caused
by damage:RF failure
U300 communication processor
Failure caused by damage:
Power-on failure
SPK speaker
Failure
caused
by
damage: No sound from
speaker
CAM pad
Failure
caused
by
damage:CAM failure
J602 Bat connector
Failure caused by
damage:
Power-on failure
LCD LCD pad
Failure caused by damage:
Display backlight failure
D700/D701/D702/D703/D704/D705
Keypad backlight
Failure caused by damage:
Keypad backlight failure
LED pad Failure caused
by damage: LED torch
failure
USB Connector Failure
caused by damage: No
port, no charging
