Micromax A121 User manual

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

A121 L2 Service Manual
1. Tools list
Tweezer
Cross screw driver
Solder
Tommy bar
Hot gun

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

A121 L2 Service Manual
Disassemble back cover with Tommy bar，as the Fig.3

A121 L2 Service Manual
4. Main board and front cover disassembly
The main components of distribution，as the fig.4

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

A121 L2 Service Manual
Open the main board and remove the RF cable con. And main FPC con..as
the FIG.6

A121 L2 Service Manual
5. Camera & light sensor disassembly
Remove the light sensor and Front camera and Back camera，as the fig.7

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

A121 L2 Service Manual
7. Sub PCBA disassembly
Remove the sub PCBA from the, as the fig.9

A121 L2 Service Manual
8. Receiver, speaker, Main MIC and Back MIC Rubber disassembly, as the
FIG.10

A121 L2 Service Manual
9. RF cable, Main FPC and vibrator disassembly

A121 L2 Service Manual
10. Structure parts diagram

A121 L2 Service Manual
11. Structure parts diagram

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.

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

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.

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.

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.

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.