Micromax A310 User manual

A310 L3 Service Manual
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1. Technical Specifications :
Particular
Remarks
Key Matrix For Flashing
NA
Chipset
MT6592
Android Version
Android 4.4
Frequency
GSM：900/1800/1900MHz UMTS：900/2100MHz
Network Mode
Dual SIM: WCDMA+GSM
ROM
8 GB
RAM
2 GB
Internal SD Card memory
5GB User available
Expandable Memory
32GB
Factory mode code
*#9527*#
2. CAUTIONS

A310 L3 Service Manual
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I. Flashing & Servicing must be undertaken by qualified personnel only.
II. Ensure all work is carried out at an anti-static workstation and that an anti-static wrist strap is worn.
III. Use only approved Tools & components as specified in the parts list.
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.

A310 L3 Service Manual
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Basic Structure of the Mobile Phone
1. PCBA Pictures of A310 Mainboard

A310 L3 Service Manual
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A310 L3 Service Manual
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A310 L3 Service Manual
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3. L3 Level trouble shooting
1) Doesn’t Power On
Solution:
There is no current when the Power Key is pressed; check SW2001 and J2002 to see if there is false soldering,
pseudo soldering or damage, if yes, Carry out resoldering or replacement;
There is no display when the Power Key is pressed, and the current stays within 100~120mA, if yes, The
problem is caused by pseudo soldering or damage of the memory; carry out repair soldering or replacement
of the memory;
When the Power Key is pressed, the display freezes in a certain interface, if yes, Upgrade the software version;
There is current when the Power Key is pressed; the current changes to 0~5mA when the key is loosened , if
yes, The problem is caused by pseudo soldering or damage of 32K or 26M crystal (X701, X1001); carry out
repair soldering or replacement of the crystal. Or, it is caused by pseudo soldering or damage of PMIC;
There is heavy current when the Power Key is pressed, if yes, Find the hot point, and replace the
corresponding material (PMIC (U701) and CPU (U201) are damaged in most cases).

A310 L3 Service Manual
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Power Key
Battery Connector

A310 L3 Service Manual
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2) Restart / Hang
Refer same to Power failure issue.
3) LCD Issues “Black screen and no display of LCD”
Solution:
Exchange the front shell to judge if the LCD itself is abnormal , if yes, Replace the LCD;
Check if the LCD connector is damaged (such as burnout) , if yes, Replace the LCD connector J1802;
Check if the diode D1803 in the backlight circuit is soldered abnormally or damaged, if yes, Carry out repair
soldering or replacement of D1803;
Check if the power inductor L1800 in the backlight circuit is soldered abnormally or damaged, if yes, Carry out
repair soldering or replacement of L1800;
Replace the backlight driver IC (U1801).
Backlight Driver IC

A310 L3 Service Manual
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Black screen, white screen and blurred screen of LCD when the backlight is OK.
Solution:
Exchange the front shell to judge if the LCD itself is abnormal, if yes, Replace the LCD;
Check if the LCD connector is damaged , if yes, Replace the LCD connector J1802;
Check if the EMI devices (LB1800, LB1801, LB1802, LB1803, LB1804) connected in series on the LCD MIPI
signal line are soldered abnormally or damaged , if yes, Carry out repair soldering or replacement of LB1800,
LB1801, LB1802, LB1803 or LB1804;
Check if the LCD power supply U1807 is abnormal or damaged, if yes, Carry out repair soldering or
replacement of U1807.

A310 L3 Service Manual
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LCD Circuit

A310 L3 Service Manual
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4) Touchpad Failure
Solution:
Exchange the front shell to judge if the TW itself is abnormal, if yes, Replace the front shell (with LCD)
Check if the TW connector is damaged, if yes, Replace the connector J1801
Check if R1835 and R1836 at TW connection have pseudo soldering , if yes, Carry out repair soldering
Replace U201
Touch Screen Circuit

A310 L3 Service Manual
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5) Proximity Sensor “Test failure of the light/proximity sensor”
Solution:
First calibrate the sensor to see if it is OK and if the I2C pull-up resistors of the acceleration sensor are OK, if
no, Carry out repair soldering of resistors R217 and R218;
Check if the silicon case for light/proximity sensor is properly installed, if no, Reinstall the silicon case for light
sensor FPC;
Check if the sensor has damage or pseudo soldering, if no, Carry out repair soldering or replacement of
U2102;
Check if R2104 and R2105 are soldered normally, if no, Carry out repair soldering or replacement of R2104 or
R2105.
Light/Proximity Sensor

A310 L3 Service Manual
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6) Accelerometer “Failure to realize automatic screen rotation during image viewing”
Solution:
Check if the IIC pull-up resistors R217 and R218 of the acceleration sensor have pseudo soldering, if yes, Carry
out repair soldering of resistors R217 and R218;
Check if the acceleration sensor U2203 has soldering damage or pseudo soldering, if yes, Carry out repair
soldering or replacement of U2203.
Acceleration Sensor

A310 L3 Service Manual
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7) Keypad
Solution: Refer same with Power-on failure
8) Charging Failures “No indication during charging”
Solution:
Replace the main FPC to check if the FPC is abnormal, if yes, Directly replace the main FPC;
Check if FB3000, R3002, C3001, C3002, D3001, LB3000, D3029 and D3030 have damage or pseudo soldering,
if yes, Carry out repair soldering or replacement of FB3000, R3002, C3001, C3002, D3001, LB3000, D3029 or
D3030;
Replace the subboard to check if the subboard is abnormal, if yes, Carry out repair soldering or replacement
of USB3004;
Check if J2004 is damaged, if yes, Carry out repair soldering or replacement of J2004.
I/O Connector

A310 L3 Service Manual
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There is charging indication, but no charging current.
Solution:
Check if the surface of the charging IC U602 has obvious damage, if yes, The charging IC is damaged, replace
U602;
Replace PL605.
Charging Management IC

A310 L3 Service Manual
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9) Main Camera/ Front Camera “Photographing and Shooting Failures”
Solution:
Check if the camera is properly installed, if no, Reinstall it;
Exchange the camera to see if the problem is solved, if yes, The problem is caused by the camera itself;
replace it;
Check if the camera connector has pseudo soldering or damage, if yes, Carry out repair soldering or
replacement of J1901/J1900;
Check if the IIC pull-up resistors R210 and R212 have pseudo soldering, if yes, Carry out repair soldering or
replacement of R210 and R212;

A310 L3 Service Manual
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Rear-facing Camera Circuit
Front-facing Camera Circuit

A310 L3 Service Manual
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10) Flash Light “Malfunction of Torch or Flashlight”
Solution:
Check if the camera can be turned on, if no, The problem is caused by the rear-facing camera; see the analysis
of camera failures;
Check if the light can turn on when battery voltage is supplied to its both ends, if yes, Replace the light U601;
Replace D1907.
Flashlight Circuit

A310 L3 Service Manual
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11) Vibrator Failures
Solution:
Check if L1200 and MOTOR3000 are damaged or have pseudo soldering, if yes, Carry out replacement or
repair soldering;
Replace the subboard.
Motor Circuit

A310 L3 Service Manual
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12) Sim“Failure to identify SIM card”
Solution:
Check if the SIM card sockets J2301 and J2302 are obviously damaged, if yes, Replace the SIM card socket;
Check if the pins of the SIM card sockets J2301 and J2302 have pseudo soldering, if yes, Carry out repair
soldering;
Check if the ground impedance of each pin of the SIM card sockets (except the ground pin) is low (lower than
grade K) , if yes, Replace the ESD device of the corresponding pin;
Check if the series resistors and magnetic beads on the network have pseudo soldering, if yes, Carry out
repair soldering.
SIM Card Socket Circuit