Mobile Phone Fault Finding Method – Problems Identification & Troubleshooting

While doing mobile phone repairing, we can do fault finding if we know different sections inside a mobile cell phone. For Example – If there is Network Problem in a mobile phone then we can easily repair the phone if we know different parts, components and their function in the Network Section.

NOTE: This Lesson is on Fault Identification and Troubleshooting of Problems. It is Not about Testing Methods. For Component Testing Methods, Please Read: Mobile Phone Repairing Testing Methods

Following are different electronic parts and components in different sections inside a mobile cell phone:

Mobile Phone Repairing

1. Network Fault

Antenna Switch, PFO, FEM, RF IC, VCO, RX-Filter, TX-Filter, RF Antenna, RF Crystal, External Antenna Socket, Network Signal and Supply Control and Interface Section.

If we know about the parts and Electronic Components present in the Network section and their function then we can easily repair the fault by looking at the code number of the faulty component in the Circuit Diagram and Different PCB Layout Diagram.

In this way we can easily make good use of circuit diagram for mobile cell phone repairing.

2. Power ON Fault

Battery (3.7 V), Battery Connector Jack, Power IC, CPU, Flash IC, S-RAM IC, RF Crystal, RF Clock Section Component, RF IC, Power ON / OFF Trigger Components.

3. Charging Fault

Charger (5-6 V), Battery (3.7 V), Charger Connector, Charger Volt Fuse, Coil, Charger Over Volt Protector, Charging IC, Power IC, Charging Regulator, Charging Volt Output Components, Charger and Charger Volt Detector Components.

4. SIM Fault

SIM Card, SIM Socket, SIM Signal and Supply Interface Components, Resistance, Coil, Power IC, CPU etc.

5. Ringer Fault

Ringer, Ringer Signal Input and Output Components, Audio Amplifier IC, Power IC, CPU etc.

6. Ear Speaker Fault

Ear Speaker, Ear Speaker Signal Components, Audio Amplifier IC, CPU, Power IC etc.

7. Micro SD Card Fault / MMC Fault

Micro SD Card, Micro Card Connector, Micro Card Detector Switch, Micro Card Detector Signal Components, CPU etc.

8. USB and Bottom Connector fault

USB and Bottom Connector, USB and Signal Interface Connector Components, USB Signal Interface IC, USB Driver IC, CPU etc.

9. Keypad Fault

Key Tip, Key Pad Dot Sheet, Key Signal Filters, Key Signal Varactors, Key Board to Key Connector, CPU etc.

10. Display Fault

LCD, LCD Connector, LCD Supply Components, LCD Signal Interface Filter IC, CPU, LCD Signal Interface Resistance etc.

11. MIC Sound Fault

MIC, MIC Interface Connection, MIC Signal and Supply Components, Power IC, CPU etc.

12. Backlight (LED) Fault

LED, Backlight Driver IC, Backlight Driver Section Components, Power IC, CPU etc.

13. Bluetooth Fault

Bluetooth Antenna, Bluetooth Driver IC, Bluetooth Section Crystal, CPU etc.

14. FM Radio Fault

Hands Free Lead, Hands Free Connector, FM and Bluetooth IC, FM Driver IC, CPU etc.

15. Vibrator Fault

Vibrator Motor, Vibration Supply Components, Power IC, Vibrator Driver IC etc.

16. Touch Screen Fault

Touch Panel / PDA Panel, Touch Panel Control IC, CPU, Signal Interface Parts etc.