Lenovo P70 Service manual

Service Manual of

Lenovo P70-A Mobile

Phone

Lenovo

Repair Manual of Lenovo P70-A Mobile Phone

Document name Service Manual of Lenovo P70-A Mobile Phone
Version: V1.0
Date: Nov 3, 2014
Document No.:
Status:

Preface

This manual is intended for online repair guidance and after-sale repair guidance of

Lenovo P70-A mobile phone produced by the Company

The content of this manual will be upgraded according to the needs of technology

development.

Copyright

The copyright of this manual belongs to Lenovo Mobile; anyone who reproduces this

manual without written consent of the Company shall bear legal responsibility.

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Repair Manual of Lenovo P70-A Mobile Phone

Content

1. Appearance ............................................................................................................................. 5

2. Layout of main board ............................................................................................................. 6

3. Baseband ................................................................................................................................. 7

4. Main adverse analysis ............................................................................................................... 8

4.1 LCD DISPLA Y ........................................................................................................................... 8

4.1.1 No display on screen after power-on ................................................................................... 8

4.1.2 LCD backlight without lighting ........................................................................................... 9

4.2 CAMERA DEFECTS ................................................................................................................... 10

4.2.1 Rear camera defects .......................................................................................................... 10

4.3 RING AND VIBRATION .............................................................................................................. 11

4.3.1 No vibration ....................................................................................................................... 1 1

4.3.2 No ring ............................................................................................................................... 12

4.4 CHARGING .............................................................................................................................. 13

4.4.1 No charging display after plugging the charger in ............................................................ 13

4.4.2 Charging shown but not full charging ............................................................................... 14

4.5 KEYBOARD AND KEYBOARD BACKLIGHT ................................................................................ 15

4.5.1 Abnormal operation of side keys ....................................................................................... 15

4.5.2 Abnormal operation of CTP keyboard ............................................................................... 16

4.6 CALLING ................................................................................................................................. 17

4.6.1 No voice heard from the other side during the call ............................................................ 17

4.6.2 No voice heard from your side during the call ................................................................... 18

4.7 POWER-ON FAILURE ................................................................................................................ 19

4.8 LCD ON WHEN CLOSE TO THE EAR DURING THE CALL; LCD OFF WHEN AWAY FROM THE EAR. 20

4.9 RADIO FREQUENCY (RF) ......................................................................................................... 21

4.10 SOFTWARE DOWNLOAD FAILURE ............................................................................................ 21

4.11 PRODUCTION CALIBRATION .................................................................................................... 22

4.11.1 AFC calibration ............................................................................................................. 22

4.11.2 AGC ............................................................................................................................... 23

4.11.3 APC ............................................................................................................................... 24

4.12 FAULT IN COMPLETE SET TEST/ REWORK ................................................................................. 26

4.12.1 Switch spectrum & PVT template with excessive standard ........................................... 26

4.12.2 High Frequency Error ................................................................................................... 27

4.12.3 High Phase Error .......................................................................................................... 27

4.12.4 Power output problems .................................................................................................. 28

4.13 3G/4G FORECAST ................................................................................................................... 29

4.13.1 RSSI _Cal ...................................................................................................................... 29

4.13.2 TPC _ Cal ...................................................................................................................... 29

4.14 3G/4G COMPREHENSIVE TEST ................................................................................................. 31

4.14.1 ACLR or SEM ................................................................................................................ 31

4.14.2 ILPC comprehensive test abnormal ............................................................................... 31

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Repair Manual of Lenovo P70-A Mobile Phone

4.14.3 Frequency Err................................................................................................................ 31

5. Disassembly Guide .............................................................................................................. 32

6. Assemble Guide ................................................................................................................... 40

3

Version

No.

Prepared by/

Modified by

Prepared/

Modified

on

Reason for

change

Main changes

1. Appearance

Repair Manual of Lenovo P70-A Mobile Phone

2. Layout of main board

Front of main board:

Back of main board:

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Repair Manual of Lenovo P70-A Mobile Phone

3. Baseband

Block diagram of hardware system

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Repair Manual of Lenovo P70-A Mobile Phone

4. Main adverse analysis

4.1 LCD display

4.1.1 Nodisplayonscreenafterpower‐on

White screen or blank screen without display; backlight

with lighting

Check the connection of LCD FPC is good and
re-assembled FPC whether phone is normal

N

Check the display is normal after replacing LCD,

N

Check whether the EMI device Z1601--Z1605 of
LCD circuit on main board is solder incompletely;
re-solder EMI device

N

Check whether there is cold solder joint on other
device around LCD and on LCD connector.

Y

OK

Y

OK

Y

OK

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Repair Manual of Lenovo P70-A Mobile Phone

4.1.2 LCDbacklightwithoutlighting

LCD backlight without lighting

Check whether the connection of FPC on
LCD module and connector on main board is
good and whether the LCD backlight is
normal after reconnection

N

Y

OK

Re-verify whether the LCD backlight is
normal after replacing LCD.

N

Check whether there are voltages more than
24V between both ends of C1612 when LCD
is lit.

N

Check the welding condition of U160 3 and
peripheral devices, including L1601,
D1601, C1612,C1611，R1605,R1606

Y

OK

Y

If the backlight circuit is
normal, it is the problem
of LCD

Y

OK

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Repair Manual of Lenovo P70-A Mobile Phone

4.2 Camera defects

4.2.1 Rearcameradefects

Can not take photos

Check to see whether the camera
module is in the right position by
disassembling and whether the module
is OK after reassembling module

N

Whether the camera is OK
after replacing the camera
module

N

Check to see whether the camera
module connector is welded well;
whether the camera is OK after
overlaying welding the connector?

N

Y

Y

OK

OK

Y

OK

Check to see whether the EMI
device is complete and welding is
in good condition; if not; repair
EMI device(Z1701—Z1705)

Check to see whether
the front camera is
abnormal

Check to see whether the main
chip U401 are normally
welded?

N

N

Recheck after overlaying welding

Y

Recheck after replacing front
camera

Re-weld or replace U401

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Repair Manual of Lenovo P70-A Mobile Phone

(

)

4.3 Ring and vibration

4.3.1 Novibration

No vibration

N

Check whether the motor is interfered by
structure; Recheck whether it is normal after
reassembling the phone.

N

Replace the motor to see whether
it is ok? Check to see whether the
circuit around the motor is
normal

R1808，C1811

N

Replace U503 chip

Y

Y

OK

OK

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Repair Manual of Lenovo P70-A Mobile Phone

4.3.2 Noring

No ring

Replace Speaker and recheck whether it is
normal?
Check to see whether the SPK circuit is
normal?(D1405,D1406,C1413,B1405,B1406,R
505,R506)

N

Use earphone to test whether there is sound; if
there is sound from earphone, there is audio
signal to input. Check whether J1803 KB
connector device is of cold solder joint; recheck
whether it is ok after re-welding，Replace the

Y

OK

Y

OK

N

Check to see whether the main chip U503 is
damaged. Replace it if damaged.

Y

OK

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