HOT !!! How To Repair Different Faults in Mobile Phones

Here I will post general fault finding methods to repair different faults
Step by Step method to repair different faults

I invite everybody to share ur knowledge

There r three types of faults in mobile phones :
1. Hardware Faults
2. Software Faults
3. Settings Faults

1. Hardware faults can be repaired by using hardware methods only i.e dry soldering, jumpering or change of SMDs,etc

2. Software faults occur in mobiles if its OS (Operating System) gets corrupted.These faults can be repaired by flashing (reinstalling software). Flashing is possible only if u have flashing boxes. It is not possible to flash a mobile without boxes
These r the common boxes used for flashing -
Nokia : UFS Box, JAF Box, MT Box, Universal Box,etc
Sony Ericsson : SE Tool Box, Cruisor,etc
Motorola : Smart Clip Box, Ultima Box, Infinity Box,etc
Samsung : NS PRO Box, UST PRO Box

3. Settings faults r due to wrong change of settings. We first try to fix the particular setting. If we cannot make out which setting has problem we reset all settings through secret codes or use 'Full Factory Reset' option in the settings menu

These r the most common faults found in mobile phones :

1. Mobile Phone Dead
2. Insert Sim Card Problem
3. Hanging Problem
4. Network Problem
5. Mic Problem
6. Ringer Problem
7. Speaker Problem
8. Vibrator Problem
9. Display Problem
10. Mobile Restart/ Switch Off Automatically Problem
11. Call Cut Off Problem
12. Charging Problem
13. Keypad Problem
14. Sim Lock/ Mobile Lock Mobile
15. Contact Service/ Contact Retailer/ Contact Manufacturer
16. Battery Discharge Problem
17. Gallery Not Opening Problem
18. Camera Problem
19. FM Radio
20. LED Problem
21. Memory Card Problem
22. Bluetooth Problem

Please dont post here jumper solutions unless necessary

I invite everybody to share ur knowledge

[SIZE="2"][COLOR="Blue"][I]How to Repair a Dead Mobile Phone :

If the mobile phone does not switch on, it is called a dead mobile.
It can be due to many reasons
1. Water damage
2. Fall down
3. Not used for a long time ( Mostly battery is down)


(1) Check the Battery. It should show 3.7 volts or as written on the battery.

(2) Check the Battery Connector
Check two things (a) Voltage coming or not (b) shorting
Note : If there is shorting then clean the circuit in ultrasonic cleaner (Remove display, camera, etc before putting it in ultrasonic cleaner )
Clean the circuit with a soft brush and make it dry with a hair dryer or blower.
If the shorting does'nt go it may be due to shorting in an ic,capaicitor or circuit. if shorting is in ic u can check it by attaching a battery then press the on-off switch keep the battery for 10-15 seconds. after that remove the battery and check which ic bacomes hot. Reball or replace that ic. If shorting is in circuit it must be removed by ultrasonic cleaner
Note - The circuit is made of three layers. if there is shorting in the middle layer it cannot be removed
(3) Check the On/Off switch & voltage at on-off switch
Note - Connect a charger. If charging is shown on display then the problem is with the on/off switch or software problem

(4) Try flashing the mobile.

(5) If flashing cannot be done then there is hardware fault we first dry solder the Flash IC & RAM IC and check in the Software. if flashing cannot be done then we dry solder/reball/replace flash ic & RAM ic.After that dry solder/reball/replace Power IC, Network IC, Crystal, CPU

How to check shorting in mobiles -

Please dont post here jumper solutions unless necessary

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HOW TO REPAIR INSERT SIM CARD PROBLEM

If after inserting the sim card, it shows the message ‘Insert sim card’ or 'insert uim card' or 'offline mode' then it is called sim card problem.

Solution :
(1) Check the Sim Card connector
(2) Clean the Sim Card connector contacts
(3) If it is Soldered Sim Connector then refresh it
with soldering iron
(4) Also check the sim card
(5) If there is Sim IC in the mobile dry solder
(6) Replace the sim IC
(7) Try Jumper Solution
(8) The problem is from Power IC or UEM IC.Dry solder/reball/change it

After dry soldering sim ic if the problem is not solved,we replace the sim ic.
If a new sim ic is not available we remove the sim ic and make this jumper on the circuit. After this throw away the sim ic
This jumper will do the work of sim ic

sir,

Get connect n enter the procedure used by all members so that a strong base with exceptional knowledge on mobile can be known to all of us.
regards
prans