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A121 L2 Service Manual

Product introduce

Model

：

A121

Product size

：

146.2*74.2*10.2mm

Platform

：

MSM8212

，

1.2GHz Quad

Memory

：

4GB+1GB (Nand&sdram+RAM

）

System

：

Android

Frequency band: WCDMA

：

900+2100

，

GSM

：

850/900/1800/1900

Battery

：

2000mAh

Charger: Travel charger

USB cable: MICRO 5PIN

Earphone

：

3.5jack

LCD&TP

：

5.0HD IPS, resolution: 1280*720

，

Capacitance TP

Camera

：

2.0M and 8.0M CMOS

Support

：

GPS

，

BT4.0

，

WIFI

，

WAPI

Support

：

3D graphics accelerator

， accelerator sensor, distance sensor, light feeling sensor

，

Double MIC noise reduction all-guides.com

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A121 L2 Service Manual

1. Tools list

 Tweezer

 Cross screw driver

 Solder

 Tommy bar

 Hot gun

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A121 L2 Service Manual

2. Battery cover disassembly

 Open the battery cover

， as the Fig. 1

3. Back caver disassembly

 Unscrew 9 screws in back cover

， as the Fig.2

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A121 L2 Service Manual

 Disassemble back cover with Tommy bar

， as the Fig.3

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A121 L2 Service Manual

4. Main board and front cover disassembly

 The main components of distribution

， as the fig.4

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A121 L2 Service Manual

 Remove 3 screws and open the LCD con. & TP con

， remove the volume key

FPC & power key FPC, as the FIG. 5 all-guides.com

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A121 L2 Service Manual

 Open the main board and remove the RF cable con. And main FPC con..as the FIG.6

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A121 L2 Service Manual

5. Camera & light sensor disassembly

 Remove the light sensor and Front camera and Back camera

， as the fig.7

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A121 L2 Service Manual

6. Power key FPC & volume key FPC disassembly

 Remove the power key FPC and volume key FPC with the iron

， as the fig.8

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A121 L2 Service Manual

7. Sub PCBA disassembly

 Remove the sub PCBA from the, as the fig.9

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A121 L2 Service Manual

8. Receiver, speaker, Main MIC and Back MIC Rubber disassembly, as the

FIG.10 all-guides.com

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A121 L2 Service Manual

9. RF cable, Main FPC and vibrator disassembly

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A121 L2 Service Manual

10. Structure parts diagram

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A121 L2 Service Manual

11. Structure parts diagram

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A121 L2 Service Manual

Repairing guide

1. LCD

 Check if the SW is correct, otherwise to upgrade the SW;

 Check the LCD if is ok, otherwise change a new LCD;

 If that the LCD loose, re-assemble the LCD and test;

 Checking the LCD connector if is ok, otherwise re-solder it or change a new one;

 Checking the circuit around the LCD connector.

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A121 L2 Service Manual

2. Camera

 Checking the camera is assemble ok, re-assemble the camera and test;

 Using the good camera to do cross test, it can check if the camera is ok;

 Checking the camera connector if is ok as below picture, otherwise to re-solder or change a new one;

 Checking the circuit around the camera connector all-guides.com

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A121 L2 Service Manual

3. Touch Pannel

 Checking the SW and upgrade the SW;

 Checking the FPC of TP and re-assemble it;

 Using the good TP to do cross test;

 Checking the TP connector, otherwise re-solder or change a new one;

 Checking the circuit around the TP connector.

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A121 L2 Service Manual

4. Ringer

 Checking the shrapnel of speaker if is ok;

 Checking the resistance of speaker if is ok, otherwise to change a new one;

 Checking the FPC if is ok;

 Checking SPK-FPC if connector with sub-board is ok.

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A121 L2 Service Manual

5. Reciever

 Checking the shrapnel of receiver if is ok;

 Checking the resistance of receiver if is ok, otherwise to change a new one;

 Checking the connector point on the main board if is ok, as below picture;

 Checking the receiver circuit if is ok.

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A121 L2 Service Manual

6. MIC and Vibrator

 Checking the MIC and Vibrator is cold soldering, re-solder it;

 Change the MIC and Vibrator;

 Checking the circuit of MIC and Vibrator;

 Checking the FPC if connect ok.

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A121 L2 Service Manual

7. Earphone

 Checking the shrapnel of earphone if is ok;

 Checking the connector point on the main board if is ok, as below picture;

 Change earphone connector;

 Checking the circuit of earphone. all-guides.com

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A121 L2 Service Manual

8. No Power On / Dead

 Checking the voltage of battery if is 3.8-4.2V and connect ok;

 Upgrade the SW;

 Checking the power on key and circuit around it

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A121 L2 Service Manual

9. No charging

 Checking the voltage of battery if is over 3.4V;

 Checking the charger and USB cable if is ok;

 Checking the USB connector and circuit if is ok.

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A121 L2 Service Manual

10. No SIM card and No memory card

 Checking the connector of T –card and SIM card;

 Change the connector of T –card and SIM card;

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A121 L2 Service Manual

11. No Nervice / Network Drop

 Checking RF line if that is broken;

 Checking RF line assemble if is ok;

Thanks

For any query or suggestion please write to [email protected]