I . FEATURES AND COMPONENTS OF THE CELLPHONE
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1. Features :

a. IMEI – International Mobile Equipment Identification code.
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A 15 character number which is the same as one on the back of the phone and
made to identify as follows.
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Example numbers : 123456 / 78 / 901234 / 5 ( *#06# )
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12 = Manufacturer 78 = Final Assembly Code
52 = Ericsson 07 = Germany
44 = Motorola 10 = Finland ( all Nokia phones )
49 = Nokia 40 = UK
67 = USA
80 = China / Arab
3456 = Type approval Code 81 = China
0518-0523 = 6110
3002 = 6150 901234 = Serial Number
5 = Spare
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b. Firmware Version – by pressing *#0000# we can determine the version, released to the market .

c. Software for different cellphones to acquire different features like ringtones, texting, games and others.

2. Main Components of the cellphone ( sample unit 3310 )
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1. A-Cover assembly of housing
2. Keymat or keypad
3. Screws
4. Display assembly of LCD ( Liquid Crystal Diode )
5. Speaker with gasket
6. PCB Assembly
Pago Pins
Bottom connector
9. Buzzer assembly
10. Power key
11. SIM card
12. Vibra assembly
13. D-cover
14. Battery connector
15. Antenna assembly
16. Type label
17. Battery
18. B-cover assembly

*II. TROUBLESHOOTING PCB ASSEMBLY ARE DEVIDED INTO 3 MODULES
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1. BASEBAND – consist of the following :
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a. Power Supply IC or CCONT IC ( CURRENT CONTROLLER )
- heart of the Baseband power distribution
- compacted voltage regulators to feed power to the whole system

b. MAD IC or CPU ( CENTRAL PROCESSING UNIT )
- controlling the Baseband function
- inside the CPU are : MCU ( Master Control Unit ), System Logic and DSP
(Digital Signal Processor) which controls radio interface and speech coding/ decoding

c. COBBA IC ( Common Base Band Analog )
- so called the Audio IC
- provides interface between the base band and the RF circuitry
- perform analog to digital conversion of the receive signal

d. RAM IC ( RANDOM ACCESS MEMORY )

e. FLASH ROM IC ( FLASH PROGRAM STORAGE )

2. RF ( RADIO FREQUENCY ) PART
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- diplexer in 3210
- duplexer in 3210 which is the COMBINER
- antenna switch in 3310, 8210, 6210 and others
- RF power amplifier
- SUMMA and CRFU3 in 3210 below models of NOKIA
- HAGAR IC in 3310 above models
- VCO ( voltage control oscillator )
- Crystal Clock and others
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3. UI ( USER INTERFACE )
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- LCD
- Keyboard
- Led
- Buzzer
- Vibra
- Speaker
- Microphone and others

III. CHIPS / PARTS USED IN CELLPHONES AND ITS CHARACTERISTICS

1. BGA type of IC , such as the CCONT or the power supply, COBBA, CPU, Flash ROM, RAM
and HAGAR. Unlike the TTL ICs, BGA ( ball grid array ) is different it has pins or balls
underneath of the component. MicroBGA components are moisture and electrostactic sensitive device which need to be handled in a special way in production.

2. CAPACITORS, another chips used in SMD ( Surface Mount Device ) type are the capacitors.
A capacitor has the ability to hold a charge of electrons, previously called a condenser.

3. Other SMD type active devices or components in cellphone are:
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Resistors. When electronics parts are manufactured to have resistance only, they are
called resistors. Besides heating when current flows through them, resistors are useful
in limiting current in circuits.

Diodes and Transistors. Design to rectify, amplify, and alter the waveshapes of
AC signals fed to them.
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4. EEPROM IC. Electronicaly Erasable Programmable Read Only Memory. It can be seen in 3210,
5110, 61xx with an eight pins mounted on PCB.
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5. OSCILLATORS. An oscillators circuit produces ac. When high-power power frequency ac
(10 to 800 Hz) is required, various types of electromagnetic alternators may be used.
For higher frequencies, in the audio and radio frequency ( AF and RF ) ranges, transistor or
tube oscillator circuits are employed.