Micromax Q346 User manual

Q346 L3 Service Manual
A) Technical Specification USB(J609)ns:
Particular
Remarks
Key Matrix For Flashing
Volume+
Chipset
SC7731
Android Ver USB(J609)n
Android 5.1
Frequency
1.3G
Network Mode
GSM：900/1800MHz WCDMA：900/2100MHz
Rom
8G
RAM
1G
Internal SD Card memory
5.4GB for End user

Q346 L3 Service Manual
Expandable Memory
32G
Factory mode code
*#1923*#
Good Earpiece volume
32ohm
Good Loudspeaker volume
8ohm
Good MIC volume
2kohm
Good Vibrator volume
40ohm
Engineering Code
*#*#83781#*#*
B) CAUTUSB(J609)NS
I. Flashing & Servicing must be undertaken by qualified personnel only.
II. Ensure all work is carried out at an anti-static workstation USB (J609) n 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 repointed correctly if Handset disassembled
VI. Electrostatic discharge can easily damage the sensitive components of electronic products.
Therefore, Service Centre must adhere the precaution which mentioned above.

Q346 L3 Service Manual
C) L3 Service Manual

Q346 L3 Service Manual

Q346 L3 Service Manual
D) Symptoms
Please Provide PCBA Level repair process for below symptoms level with PCBA component images and Schematic
diagrams
1、Unable to load Software:
It might be the poor soldering of USB (J609) Connector, please check the soldering quality of USB (J609)
Connector first, and then check the related diagram.
Solution：
1. Use a fresh data cable.
2. Check the USB (J609) connector and its soldering quality, and then check the volume of J607.
3. Re-Solder the USB (J609) connector.
4. Re-Solder the 26M(X901) crystal or change it.
5. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
2、No power on
Solution：
1. Check resistor R619 from net PWRKEY to net PBINT is correct or not.
2. Power on the handset with DC to verify its current is correct or not, check the diagram of VBAT &VBUS
is shorted or damaged.
3. Re-Solder the 26M(X901) crystal or change it.
4. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
3、Not charging:
Solution：
1. Use a fresh USB data cable or charger, re-solder the USB (J609) connector.
2. Check charge mosfet (Q501) is poor soldering, shorted or damaged.
3. Check Mid PIN of battery connector is poor soldering or not, check the related component is shorted,
broken or not side key might be broken, (Q501 might be broken).
4. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
4、LCD / Display problem:
Solution：
1. Re-Solder the LCD or change it.
2. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
5、VIBRATOR is not working
Solution：
1. Assembly the vibrator or change it.
2. Check the vibrator circuit soldering quality.
3. Re-Solder the CPU (U0100) or change it.
6、Camera is not working
Solution：
1. Re-Solder the camera or change it.
2. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
7、MIC no sound:
Solution：
1. Assembly the micphone or change it.
2. Check the micphone circuit soldering quality
3. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
8、Receiver not working:
Solution：
1. Assembly the receiver or change it.
2. Check the receiver circuit verify it is shorted with grounding or not.
3. Check R714/R715/C712/C713/RV707/RV708
4. Re-Solder the CPU (U0100) or change it.
9、Speaker not working:
Solution：
1. Assembly the speaker or change it.
2. Check the speaker circuit verify it is shorted with grounding or not.
3. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
10、FM not working:
Solution：
1. Check phone jack (J701).
2. Check the FM circuit (built-in) soldering quality.
3. Re-Solder the CPU (U0100) or change it.
11、BT is not working fine:

Q346 L3 Service Manual
Solution：
1. Check BT antenna connection.
2. Check the BT circuit soldering quality.
3. Re-Solder the CPU (U0100) or change it.
12、Can’t detect the SIM card:
Solution：
1. Check the connection of SIM card or change a fresh SIM card to verify it.
2. Check soldering quality of the SIM connector
3. Check the SIM diagram to verify whether component is shorted with grounding, the component missed
or broken.
4. Re-Solder the CPU (U0100) or change it.

Q346 L3 Service Manual
13、RF module:
Solution：
1. Flash the SW.
2. Check the GSM antenna connection.
3. If there was no signal, then re-solder or change the RF PA.
4. Re-solder the CPU (U0100) or change it

Q346 L3 Service Manual
Thanks
For any Query or suggestion, Please write to [email protected]