Parts of a Mobile Cell Phone and Their Function (Big Parts)

There are all kinds of parts and electronic components in a mobile cell phone. These parts and components can be divided into Big Parts and Small Parts. This article explains all about big parts and components in a mobile cell phone and their function.

When learning how to repair a mobile cell phone, it is important to identify its parts and understand their function. Here I must also remind you that any PCB of a mobile phone is divided into 2 sections namely: Network Section; and Power Section. Have a look at the image below to understand PCB of a mobile cell phone.

Mobile Phone PCB Diagram with Parts

Big Parts of a Mobile Cell Phone and Their Function:

1. Antenna Switch: It is found in the Network Section of a mobile phone
   

   Cell Phone Antenna Switch
   and is made up of metal and non-metal. In GSM sets it is found in white color and in CDMA sets it is found in golden metal.
   Work: It searches network and passes forward after tuning.
   Faults: If the Antenna Switch is faulty then there will be no network in the mobile phone.
2. P.F.O: It is found near the Antenna Switch in the Network Section of the
   

   Cell Phone PFO
   PCB of Mobile Phone. It is also called P.A (Power Amplifier) and Band Pass Filter.
   Work: It filters and amplifies network frequency and selects the home network.
   Faults: If the PFO is faulty then there will be no network in the mobile phone. If it gets short then the mobile phone will get dead.
3. RF IC / Hagar / Network IC: This electronic component found near
   

   Cell Phone Network IC / RF IC
   the PFO in the Network Section of a Mobile Phone. It is also called RF signal processor.
   Work: It works as transmitter and receiver of audio and radio waves according to the instruction from the CPU.
   Faults: If the RF IC is faulty then there will be problem with network in the mobile phone. Sometimes the mobile phone can even get dead.
4. 26 MHz Crystal Oscillator: It is found near the PFO in the Network
   

   Mobile Phone 26 MHz Crystal Oscillator
   Section of a Mobile Phone. It is also called Network Crystal. It is made up of metal.
   Work: It creates frequency during outgoing calls.
   Faults: If this crystal is faulty then there will be no outgoing call and no network in the mobile phone.
5. VCO: It is found near the Network IC in the Network Section of a Mobile
   

   Mobile Phone VCO
   Phone.
   Work: It sends time, date and voltage to the RF IC / Hager and the CPU. It also creates frequency after taking command from the CPU.
   Faults: If it is faulty then there will be no network in the mobile phone and it will display “Call End” or “Call Failed”.

6. RX Filter: It is found in the Network Section of a Mobile Phone.
   

   Mobile Phone RX Filter
   Work: It filters frequency during incoming calls.
   Faults: If it is faulty then there will network problem during incoming calls.

7. TX Filter: It is found in the Network Section of a Mobile Phone.
   

   Mobile Phone TX Filter
   Work: It filters frequency during outgoing calls.
   Faults: If it is faulty then there will network problem during outgoing calls.

8. ROM: It is found in the Power Section of a Mobile Phone.
   

   Mobile Phone ROM
   Work: It loads current operating program in a Mobile Phone.
   Faults: If ROM is faulty then there will software problem in the mobile phone and the set will get dead.

9. RAM: It is found in the Power Section of a Mobile Phone.
   

   Mobile Phone RAM
   Work: It sends and receives commands of the operating program in a mobile phone.
   Faults: If RAM is faulty then there will be software problem in the mobile phone and it will get frequently get hanged and the set can even get dead.

10. Flash IC: It is found in the Power Section of a Mobile Phone. It is also
    

    Cell Phone Flash IC
    called EEPROM IC, Memory IC, RAM IC and ROM IC.
    Work: Software of the mobile phone is installed in the Flash IC.
    Faults: If Flash IC is faulty then the mobile phone will not work properly and it can even get dead.

11. Power IC: It is found in the Power Section of a Mobile Phone. There are
    

    Cell Phone Power IC
    many small components mainly capacitor around this IC. RTC is near the Power IC.
    Work: It takes power from the battery and supplies to all other parts of a mobile phone.
    Faults: If Power IC is faulty then the set will get dead.

12. Charging IC: It is found in the Power Section near R22.
    

    Cell Phone Charging IC
    Work: It takes current from the charger and charges the battery.
    Faults: If Charging IC is faulty then the set will not get charged. If the Charging IC is short then the set will get dead.

13. RTC (Simple Silicon Crystal): It is Real Time Clock and is found in
    

    Mobile Phone RTC (Real Time Clock)
    the Power Section near Power IC. It is made up of either metal or non-metal. It is of long shape.
    Work: It helps to run the date and time in a mobile phone.
    Faults: If RTC is faulty then there will be no date or time in the mobile phone and the set can even get dead.

14. CPU: It is found in the Power Section. It is also called MAD IC, RAP IC
    

    Cell Phone CPU
    and UPP. It is the largest IC on the PCB of a Mobile Phone and it looks different from all other ICs.
    Work: It controls all sections of a mobile phone.
    Faults: If CPU is faulty then the mobile phone will get dead.

15. Logic IC / UI IC: It is found in any section of a mobile phone. It has 20
    

    Cell Phone Logic IC
    pins or legs. It is also called UI IC and Interface IC.
    Work: It controls Ringer, Vibrator and LED of a mobile phone.
    Faults: If Logic IC / UI IC is faulty then Ringer, Vibrator and LED of mobile phone will nor work properly.

16. Audio IC: It is found in Power Section of a mobile phone. It is also
    

    Cell Phone Audio IC
    called Cobba IC and Melody IC.
    Work: It controls Speaker and Microphone of a mobile phone.