Micromax X771 Service Manual Download Page 6

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Model X771

L3 Service Manual

Solution:

A-

The common breakdown mainly does not work for the pressed key, the pressed key expiration. May defer to the

schematic diagram to examine whether by short circuit, abruption phenomenon. Or examined whether

underneath Dome has the foreign matter.

Charging

Solution:

A-

Check if the charging IC U600 is abnormal, if yes, Carry out repair soldering or replacement;

B-

Check if the resistors R601 are abnormal, if yes, Carry out repair soldering or replacement;

Summary of Contents for X771

Page 1: ...sion NA Frequency GSM 850 900 1800 1900 Network Mode Dual SIM GSM ROM 32Mb RAM 32Mb Internal SD Card memory NA Expandable Memory 32 GB Factory mode code 629 2 CAUTIONS I Flashing Servicing must be und...

Page 2: ...BT signal J800 J802 SIM1 SIM2 card socket Failure caused by damage Failure to identify GSM U600 charge IC Failure caused by damage Failure to No indication during charging ANT1 ANT2 GSM PAD Failure ca...

Page 3: ...add trouble shooting Repairing steps against below given symptoms Images must paste against every suggested troubleshooting hint 1 Doesn t Power On GOLD_MIC MIC pad Failure caused by damage No sound w...

Page 4: ...urrent 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 26M crustal Y200 carry out repair soldering or...

Page 5: ...L3 Service Manual Solution A Exchange the front shell to judge if the LCD itself is abnormal if yes Replace the LCD B Replace the CPU U300 4 Touchpad NA 5 Proximity Sensor NA 6 Accelerometer NA 7 Keyp...

Page 6: ...the schematic diagram to examine whether by short circuit abruption phenomenon Or examined whether underneath Dome has the foreign matter 8 Charging Solution A Check if the charging IC U600 is abnorma...

Page 7: ...Model X771 L3 Service Manual C Replace the U300 9 USB Solution U300 R601 U600...

Page 8: ...damaged or pseudo soldering if yes Carry out repair soldering or replacement of the material B Check if the charging IC U600 R601 is abnormally soldered or damaged if yes Carry out repair soldering or...

Page 9: ...e Manual Solution A Check if the camera is properly installed if yes Reinstall it B Exchange the camera to see if the problem is solved if yes The problem is caused by the camera itself replace it 11...

Page 10: ...lip which will affect coupling of RF signal further resulting in low coupling power This problem can be solved by replacing the damaged component D Damage of component material in the RF circuit which...

Page 11: ...WI FI NA 17 Bluetooth Solution A Exchange the BT ANT to see if the problem is solved if yes It is the problem of the BT ANT B The repairman can check item by item according to the signal trend in the...

Page 12: ...is solved if yes It is the problem of the earphone B Exchange the earphone jack to see if the problem is solved if yes It is the problem of the earphone jack C The repairman can check item by item acc...

Page 13: ...lity if yes Replace the earphone jack B Check if L401 L402have pseudo soldering if yes Carry out repair soldering C Replace U300 21 Outgoing Audio MIC Solution A Exchange the MIC to see if the problem...

Page 14: ...ng Audio Earpiece Solution A Visually inspect the earphone jack to see if it is abnormal if yes Replace the earphone jack B Check if L401 L402 L400 have pseudo soldering if yes Carry out repair solder...

Page 15: ...ution A Exchange the speaker to see if the problem is solved if yes It is the problem of the speaker B Check if U400 U401 have pseudo soldering or damage if yes Replace U400 U401 C Replace U300 Earpho...

Page 16: ...Model X771 L3 Service Manual 24 SD Card Solution A Exchange the J801 to see if the problem is solved if yes It is the problem of the TF socket B Replace U300 U300 J801...

Page 17: ...Model X771 L3 Service Manual 25 SIM Card Solution C Exchange the J800 or J802 to see if the problem is solved if yes It is the problem of the sim socket D Replace U300 U300 J800 J802...

Page 18: ...Model X771 L3 Service Manual Thanks For any Query or suggestion Please write to tech help micromaxinfo com...