Collection Mobile Tips & Tricks

[JannatLui]

How to repair dead phone

Problems or trouble typically found on mobile phones can be categorized into
Three damage categories, namely:
1. Software Problem category
2. Hardware Problem category
3. Problem Category his SW and HW
Phone problems and solutions
1. Total dead cell phone
Mobile phones exist three kinds of die total, die total because of
· Die alone,
· Total death due to falls, and
· Death total for the taxable water.
a. Total death because death itself.
Handling:
The first can be done early steps following
- Remove the battery and plug in again, or try using another battery and try turn it
- Check the battery connector and try the press to see the level of flexible or not,
replace damaged when new.
- Connect the charging of the phone, when the indicator on the phone in and still will not turn on, then obviously you can not live on mobile phones because of interference from IC PA (Power Amplifier). After IC PA revoked your mobile phone can turn it on again. And so no signal will be installed a new PA IC.
- When the tide does not exist and charging indicator on the phone still does not want to live on should be conducted further tests using power supply. But there may also have an ugly tin on the PCB, remove the IC PA solution, then clean the tin on the PCB where IC PA stick, replace the old IC PA, HP switch, it must be a flame.
Examination with power supply:
Necessary power supply on a scale of 1 ampere ampere (A) or 1000 mA.
With the aim that the examination can be more easily and clearly.
The steps are as follows:
- Connect the cable from the power supply to the mobile phone battery connector of at least three wires, with a negative sequence, BSI and positive. (Black, green and red)
- Navigate volt power supply at 3.6 V (or in accordance with tolerance Hp-0.5 V)
- Mobile phones in the state of OFF, and press the button on
- If the current (amperage) in a digital ampere dipower supply pointer when the button is pressed on, it just means there's still a problem on its hardware (HW), it is necessary to check the components on / off until the battery.
- When the ampere when the button is pressed on, up about? 50 mA, then the problem that occurs is a matter of software (SW), then you need to do is re-programmed HP (flash) or program is upgraded to higher versions.
b. Total death from falls.
Handling:
- HP may not be tested by using the power supply, but HP should be dismantled first, heated, and repositioned back to the location / position of the components has changed as a result of HP fell.
- After that, the new HP using the power supply should be tested to determine damage to the Hardware (HW) / Software (SW).
- Most likely a damaged components as a result of the fall is the HP PA IC / IC Power.
c. Total death due to hit the water.
Handling:
- For taxable HP water is also the first time should not be tested by using the power supply, because the risk of short circuit occurs between the components in water, but must first HP divakum, heated, or by first diblower given IPA cleaning liquid, can also use the grain silica to absorb the water that existed at HP.
- After HP confirmed it was dry, then we should use the power supply to determine the damage occurred on the Hardware (HW) or Software (SW).
- At HP's exposed to water, usually there is damage to HPnya accessories.
2. Total die because of IC phone UI.
In HP's case like this then requires test equipment that is power supply.
The steps are as follows:
- Connect the power supply on the phone, give the voltage (volts) equal to 3.6 V (or in accordance with tolerance Hp-0.5 V)
- At the time the phone is in off state, refer to the power supply needles amperes will increase by 100mA.
- The phone will start, LED lights, VIBRA vibrate.
Handling:
- Remove the IC UI, then turn on the phone.
- Then there is the display on the LCD mobile phone "Insert SIM Card".
- Put new IC UI.
- Turn on the phone, the phone will work fine.
3. Total dead cell phone because the CPU IC.
To determine whether the cell phone because the IC die total CPU is as follows:
- Give the voltage (volts) on the phone by using the power supply of 3.6 V (or in accordance with tolerance Hp-0.5 V).
- At the time the phone is not turned on, the needle ampere silent, but if the phone is switched on then the needle will rise 100mA amperes.
Handling:
- If the IC CPU is still in good condition, then we only need to heat the IC CPU by using a blower, but if the CPU IC is damaged, then we need to replace with a new CPU IC. Before we replace our CPU IC must first have the anti-hot glue and liquid glue crusher anti-heat, because the CPU IC is protected by anti-heat glue, after we destroy the anti-hot glue, then we can heat (blower) CPU IC for a new replacement. Similarly, after we replace it with a new CPU IC then we need to give more anti hot glue to protect the new CPU IC we replace it.
4. Total dead cell phone when we call.
For testing we use the power supply by way of:
- Connect the phone with power supply, give the voltage (volts) equal to 3.6 V (or in accordance with tolerance Hp-0.5 V) on the phone.
- Needles amperes will not move when the phone is still in a state of death.
- We turn on the phone and then used to make calls, then the needle will show the number of amperes above 400mA.
Handling:
- Replace with a new IC PA, after re-testing was done as above, if the needle test results show the figures below 400mA amperes, the phone is in good condition.

 

[JannatLui]

How to Work HandPhone

1.3 Introduction

Before you go any further about repairing mobile phones, of course, you must first understand the working principle of mobile phones in order to simplify the process of analysis of damage to the phone.

In this chapter will be discussed in broad outline and in general, because the development of mobile technology today is always changing.

Center 2.3 command processing input / output.


3.2.1 Command input.


Each time you make an order to the phone, for example typing an sms, play games, changing phone settings, voice recording, photos, and others. All of the above command is a command from the mobile phone users, which can pass the command-like device: keypad, camera, infra red, Bluetooth. All input commands will be accepted by the CPU, then the CPU will process all the input commands. CPU can process all the input commands based on system operating data contained in the IC flash. IC flash will store the input data when commanded by the CPU, RAM, while the IC will accept data from the CPU for a while.

3.2.1 Command Output.

CPU will provide overall command of the command input, the command from the CPU is very universal in the overall mobile phone navigation system, for example: giving the order to display graphical information on the LCD, giving orders to the UI (vibrator, buzzer, LED), gives orders to the power supply voltage to meretribusikan , and others.

3.3 Power Supply


3.3.1 Power up / down (On / Off)


The process to turn the phone is not the same as ordinary electronic circuits such as radio, etc. TV. At almost the same phone system with a computer, where the process does not turn on or turn off by disconnect power to the power supply. In the actual computer system if given the power, the system has functioned only in the inactive state, when in analogikan to humans in a state of sleep, which the system will be ready whenever given the command to activate all systems. That's because when the phone has the battery then plug in battery voltage will go straight to the IC power supply, while at the same power supply IC will provide voltage to the processor. SW circuit On / Off cell phone you can see in the image of this diawah.


3.3.1 Distribution voltage

Circuits in cell phones there are many subsystems, which each sub-system has a voltage supply needs of different and at each voltage when the system will be given when necessary. Power given by the first mobile phone battery, the voltage from battrey will continue to power supply IC, the IC power supply voltage supplylah all will be provided depending on needs.

3.3.1 Battery Charging

Mobile phone battery charging process is very thorough at all, whereby the charging system will be computerized. Battery voltage will be in diteksi by the IC power supply and CPU, if the battery in a full state of the phone will reject the filling of the transformer charger. This charging system is processed by charging IC.

3.4 Transmission of information data


Basically, a transmission system in communication systems, there are two systems, the reception (receiver) that serves as reception of data or voice information, alphanumeric data and graphics from the base station to the mobile phone. While the transmitting (Tx) functions as a voice or data transmission information, alphanumeric data, graphics and network registration process

3.4.1 The registration process network


3.4.1.1 Initialization


The first time you make phone calls called by the initialization process. This occurs when you first activate your phone. You'll get a connection from the site terdekekat sell, then the cellular network will perform checks your account or membership is still active or not, then your calls will be processed further.

3.4.1.2 Inspection frequency list


Your phone will check the list of frequencies on your SIM. Inspection covers carrie frequency flow quality, then look for Broadcash Control Channel or BCCH. Each BCCH will transmit a unique data markers, membedan between AMPS and GSM. In the AMPS system uses a dedicated radio frequency system in each cell, whereas on all GSM frequencies can carry information, but more important is the channel used to stream data rather than radio frequency

3.4.1.3 Identification of information


Base station or Broadcash Control Center will continue to deliver for the identification of information about the sell the site. The identity of the wireless network is Carreier itself, then the area code location, and frequency yag used, as well as information about the surrounding cells. All information is used to determine whether your phone is active and in need of service. BCCH is not a radio frequency didedicated. BBCH will use the channel that will carry information in the form of bits at all frequencies within a cell.

3.4.1.4 Control Channel Control Inspection Broadcash


Cell phone radio frequencies will conduct examination bradcash control channel, where your phone will send a signal to review whether the signals are still within range. The phone will be like a radio scanning the entire list of BCCH frequencies one by one and check the signal reception. Measurements will be conducted at each level of the channel. Cell site will send a strong signal to your phone. Meanwhile in broadcash control channel is a mobile data stream from the monitor did ase station called frequency control or frequency control channel burs burs (FCCB). Your mobile phone signals will synchronize with the system provider with wireless connection means. Once your phone has been communicating with the base station, then everything is ready for use.

3.4.2. Transmitting information data


3.4.2.1. signal processing of voice data, graphics, alphanumeric.

While mobile phone users are communicating, then the sound wave signal generated by mobile users will travel through the air. Gelobang voice signal will be received by the microphone to be converted into electromagnetic waves. And will proceed to the audio processor to be strengthened and processed.

If mobile phone users to sms, then type the command on the keyboard by mobile phone users will be processed by the CPU (Central Proccesor Unit)

3.4.2.2. changes in the digital signal into an analog signal (D / A converter).


In this section the data signal information is converted into an analog signal form. Because the RF section is still using an analog signal is shaped in part while the main processor in the form of a digital character. This needs to be an adjustment between two different characters that can be interconnected.

Furthermore, the data signal information already in will continue to convert the RF section.

3.4.2.3. Mixing the data signal with the carrier signal.


Information data signal will be sent to the base station, surely there must be a data signal carrying the information. Therefore, the information data signal will be mixed with the carrier by the RF signal processor. Carrier signal on GSM technology has a 900-1900 MHz frequency range, these waves are initially generated by the VCO, where the VCO will generate a wave of 3420-3840 MHz, which would then be in if the RF processor.

After the data signal information mixed with a carrier signal will then proceed to the section is called the modulation penguatan.sistem.

3.4.2.4. Strengthening end


Signal data information that has been mixed with the carrier signal will be received by the base station, while the distance to the mobile phone base stations far enough. Then the signal has to be really strong to be received by the base station. Then the signal must be reinforced by the PA Power Amplyfier. When strengthening the end of the delivery is not functioning properly then the phone will not be able to register network to the operator, this is caused because the base station can not receive the data signal information from mobile phones.

3.4.2.5. Distribution of Transmission lines


Once confirmed then the signal will be continued to the antenna switch for connecting to the antenna. Antenna switches can be in analogikan like airports, where in the data transmission of information in cell phones, there are two pathways, namely receiving and transmitting. So without the antenna switch on the received signal with the signal to be emitted will collide with each other, because there is only on GSM technology, there is one lane with a system called TDMA.

3.4.2.6. Transmitting to the base station


The next signal will be emitted through the antenna to the base station. Antenna will determine the outcome of the broadcast, then the signal is weak or strong depending on the quality antennanya.

3.4.3. Receipt of information data.


3.4.3.1. Receiving data from the base station


Signal emitted by the base station information to be received in advance by phone antennas. And then be forwarded on to the antenna switch for forwarded to the LNA.

3.4.3.2. Distribution of transmission lines


In order for transmitting signals do not collide with the signal reception, it will be first divided transmission signal by the antenna switch.


3.4.3.3. Strengthening early


So that the signal can be received well by the RF signals emitted by base stations will be strengthened first by the LNA (Low Noise Amplyfier). LNA not only functioned as a reinforcement, but can enable the cutting noise (sigh).


3.4.3.4. Separation of the carrier signal with the signal information


Signals generated by the LNA still mixed with a carrier signal, in order to be processed by the DSP (Digital Signal proccersor) then the data signal information must be separated first by the RF processor. This system is called the frequency.


3.4.3.5. changes in the analog signal into digital signal (D / A converter).


In this section the data signal information is converted into digital signal form. Because the RF section is still using an analog signal is shaped in part while the main processor in the form of a digital character. This needs to be an adjustment between two different characters that can be interconnected.

Furthermore, the data signal information already in the convert will be continued to the main processor (CPU). When the data signal is a voice tersubut information will be continued to the audio amplifier.


3.4.3.6. Strengthening the end of the voice signal


When the data signal information is voice data, it will be reinforced by an audio amplifier terlabih first before continuing to the speakers. Audio signal will be converted into electromagnetic waves, then needs to connect to the speakers so that the electromagnetic signals into sound signals which propagate in the air to be heard by people ears.

 

[JannatLui]

How to Work HandPhone

1.3 Introduction

Before you go any further about repairing mobile phones, of course, you must first understand the working principle of mobile phones in order to simplify the process of analysis of damage to the phone.

In this chapter will be discussed in broad outline and in general, because the development of mobile technology today is always changing.

Center 2.3 command processing input / output.


3.2.1 Command input.


Each time you make an order to the phone, for example typing an sms, play games, changing phone settings, voice recording, photos, and others. All of the above command is a command from the mobile phone users, which can pass the command-like device: keypad, camera, infra red, Bluetooth. All input commands will be accepted by the CPU, then the CPU will process all the input commands. CPU can process all the input commands based on system operating data contained in the IC flash. IC flash will store the input data when commanded by the CPU, RAM, while the IC will accept data from the CPU for a while.

3.2.1 Command Output.

CPU will provide overall command of the command input, the command from the CPU is very universal in the overall mobile phone navigation system, for example: giving the order to display graphical information on the LCD, giving orders to the UI (vibrator, buzzer, LED), gives orders to the power supply voltage to meretribusikan , and others.

3.3 Power Supply


3.3.1 Power up / down (On / Off)


The process to turn the phone is not the same as ordinary electronic circuits such as radio, etc. TV. At almost the same phone system with a computer, where the process does not turn on or turn off by disconnect power to the power supply. In the actual computer system if given the power, the system has functioned only in the inactive state, when in analogikan to humans in a state of sleep, which the system will be ready whenever given the command to activate all systems. That's because when the phone has the battery then plug in battery voltage will go straight to the IC power supply, while at the same power supply IC will provide voltage to the processor. SW circuit On / Off cell phone you can see in the image of this diawah.


3.3.1 Distribution voltage

Circuits in cell phones there are many subsystems, which each sub-system has a voltage supply needs of different and at each voltage when the system will be given when necessary. Power given by the first mobile phone battery, the voltage from battrey will continue to power supply IC, the IC power supply voltage supplylah all will be provided depending on needs.

3.3.1 Battery Charging

Mobile phone battery charging process is very thorough at all, whereby the charging system will be computerized. Battery voltage will be in diteksi by the IC power supply and CPU, if the battery in a full state of the phone will reject the filling of the transformer charger. This charging system is processed by charging IC.

3.4 Transmission of information data


Basically, a transmission system in communication systems, there are two systems, the reception (receiver) that serves as reception of data or voice information, alphanumeric data and graphics from the base station to the mobile phone. While the transmitting (Tx) functions as a voice or data transmission information, alphanumeric data, graphics and network registration process

3.4.1 The registration process network


3.4.1.1 Initialization


The first time you make phone calls called by the initialization process. This occurs when you first activate your phone. You'll get a connection from the site terdekekat sell, then the cellular network will perform checks your account or membership is still active or not, then your calls will be processed further.

3.4.1.2 Inspection frequency list


Your phone will check the list of frequencies on your SIM. Inspection covers carrie frequency flow quality, then look for Broadcash Control Channel or BCCH. Each BCCH will transmit a unique data markers, membedan between AMPS and GSM. In the AMPS system uses a dedicated radio frequency system in each cell, whereas on all GSM frequencies can carry information, but more important is the channel used to stream data rather than radio frequency

3.4.1.3 Identification of information


Base station or Broadcash Control Center will continue to deliver for the identification of information about the sell the site. The identity of the wireless network is Carreier itself, then the area code location, and frequency yag used, as well as information about the surrounding cells. All information is used to determine whether your phone is active and in need of service. BCCH is not a radio frequency didedicated. BBCH will use the channel that will carry information in the form of bits at all frequencies within a cell.

3.4.1.4 Control Channel Control Inspection Broadcash


Cell phone radio frequencies will conduct examination bradcash control channel, where your phone will send a signal to review whether the signals are still within range. The phone will be like a radio scanning the entire list of BCCH frequencies one by one and check the signal reception. Measurements will be conducted at each level of the channel. Cell site will send a strong signal to your phone. Meanwhile in broadcash control channel is a mobile data stream from the monitor did ase station called frequency control or frequency control channel burs burs (FCCB). Your mobile phone signals will synchronize with the system provider with wireless connection means. Once your phone has been communicating with the base station, then everything is ready for use.

3.4.2. Transmitting information data


3.4.2.1. signal processing of voice data, graphics, alphanumeric.

While mobile phone users are communicating, then the sound wave signal generated by mobile users will travel through the air. Gelobang voice signal will be received by the microphone to be converted into electromagnetic waves. And will proceed to the audio processor to be strengthened and processed.

If mobile phone users to sms, then type the command on the keyboard by mobile phone users will be processed by the CPU (Central Proccesor Unit)

3.4.2.2. changes in the digital signal into an analog signal (D / A converter).


In this section the data signal information is converted into an analog signal form. Because the RF section is still using an analog signal is shaped in part while the main processor in the form of a digital character. This needs to be an adjustment between two different characters that can be interconnected.

Furthermore, the data signal information already in will continue to convert the RF section.

3.4.2.3. Mixing the data signal with the carrier signal.


Information data signal will be sent to the base station, surely there must be a data signal carrying the information. Therefore, the information data signal will be mixed with the carrier by the RF signal processor. Carrier signal on GSM technology has a 900-1900 MHz frequency range, these waves are initially generated by the VCO, where the VCO will generate a wave of 3420-3840 MHz, which would then be in if the RF processor.

After the data signal information mixed with a carrier signal will then proceed to the section is called the modulation penguatan.sistem.

3.4.2.4. Strengthening end


Signal data information that has been mixed with the carrier signal will be received by the base station, while the distance to the mobile phone base stations far enough. Then the signal has to be really strong to be received by the base station. Then the signal must be reinforced by the PA Power Amplyfier. When strengthening the end of the delivery is not functioning properly then the phone will not be able to register network to the operator, this is caused because the base station can not receive the data signal information from mobile phones.

3.4.2.5. Distribution of Transmission lines


Once confirmed then the signal will be continued to the antenna switch for connecting to the antenna. Antenna switches can be in analogikan like airports, where in the data transmission of information in cell phones, there are two pathways, namely receiving and transmitting. So without the antenna switch on the received signal with the signal to be emitted will collide with each other, because there is only on GSM technology, there is one lane with a system called TDMA.

3.4.2.6. Transmitting to the base station


The next signal will be emitted through the antenna to the base station. Antenna will determine the outcome of the broadcast, then the signal is weak or strong depending on the quality antennanya.

3.4.3. Receipt of information data.


3.4.3.1. Receiving data from the base station


Signal emitted by the base station information to be received in advance by phone antennas. And then be forwarded on to the antenna switch for forwarded to the LNA.

3.4.3.2. Distribution of transmission lines


In order for transmitting signals do not collide with the signal reception, it will be first divided transmission signal by the antenna switch.


3.4.3.3. Strengthening early


So that the signal can be received well by the RF signals emitted by base stations will be strengthened first by the LNA (Low Noise Amplyfier). LNA not only functioned as a reinforcement, but can enable the cutting noise (sigh).


3.4.3.4. Separation of the carrier signal with the signal information


Signals generated by the LNA still mixed with a carrier signal, in order to be processed by the DSP (Digital Signal proccersor) then the data signal information must be separated first by the RF processor. This system is called the frequency.


3.4.3.5. changes in the analog signal into digital signal (D / A converter).


In this section the data signal information is converted into digital signal form. Because the RF section is still using an analog signal is shaped in part while the main processor in the form of a digital character. This needs to be an adjustment between two different characters that can be interconnected.

Furthermore, the data signal information already in the convert will be continued to the main processor (CPU). When the data signal is a voice tersubut information will be continued to the audio amplifier.


3.4.3.6. Strengthening the end of the voice signal


When the data signal information is voice data, it will be reinforced by an audio amplifier terlabih first before continuing to the speakers. Audio signal will be converted into electromagnetic waves, then needs to connect to the speakers so that the electromagnetic signals into sound signals which propagate in the air to be heard by people ears.

 

[JannatLui]

Cellphone Basics

EXPLANATION OF THE BASIC THEORY OF OPERATION OF A MOBILE PHONE IN A VERY SIMPLE WAY:​

HAVE YOU EXPERIENCED THE FACT THAT IN A MUSIC LISTENED FROM A VERY LONG DISTANCE, THE SOUNDS OF DRUMS ARE LESS AUDIBLE THAN THE SOUNDS OF OTHER SHARP INSTRUMENTS LIKE GUITAR ? YES THIS IS BECAUSE THE SOUND OF A DRUM IS A LOW FREQUENCY SIGNAL AND LOW FREQUENCIES CANNOT TRAVEL LONG DISTANCES EASILY WHILE THE HIGH FREQUENCIES LIKE THE SOUND OF GUITAR OR OTHER STRING INSTRUMENTS CAN ! SEE HOW THIS IS APPLIED IN THE RADIO, TV AND MOBILE TECHNOLOGY FOR YOURSELF. AFTER ALL THE MOBILE PHONE IS ALSO A RADIO TELEPHONE ! THE BROAD MEANING OF THE WORD "RADIO" IS WIRELESS. THE PRINCIPLE OF A MOBILE PHONE CAN BE COMPARED WITH THAT OF A RADIO OR A TELEVISION SYSTEM.

There are two parts in mobile phone 1. is Transmiting & 2. is Receiving

TRANSMITTING PART..

THE VOICE SIGNAL WHICH IS BASICALLY IN THE FREQUENCY RANGE OF 15 HERTZ TO ABOUT 20 KILOHERTZ (1KILOHERTZ=1000 HERTZ)AND IS IN THE LOWEST FREQ.BAND IN THE NORMAL FREQUENCY SPECTRUM, WHICH IS REQUIRED TO BE SENT TO THE OTHER MOBILE PHONE IS FIRST CONVERTED FROM ANALOG TO DIGITAL TYPE OF SIGNAL AND IS THEN MIXED WITH A VERY HIGH FREQUENCY SIGNAL IN THE RANGE OF HUNDREDS OF MEGAHERTZ (1 MEGAHERTZ = 1000KILOHERTZ=1000X1000 HERTZ=1000000 HERTZ) IN THE MOBILE PHONE , THIS IS CALLED MODULATION, WHICH MEANS CHANGING THE AUDIO SIGNAL BY ADDING ANOTHER VERY HIGH FREQUENCY TO IT , THE HIGH FREQUENCY BEING USED AS CARRIER FREQUENCY TO CARRY THE VOICE OR THE AUDIO SIGNAL. THIS IS DONE TO MAKE IT POSSIBLE TO BE SENT THRO' AIR TO THE NEAREST TOWER OF THE SERVICE OPERATOR. THE BASIC PRINCIPLE BEING THAT THE HIGH FREQUENCIES CAN TRAVEL LONGER DISTANCES EASILY.

RECEIVING PART

IN THE RECEIVING PART, THE REVERSE (DE-MODULATION) IS REQUIRED TO BE DONE. THE RECEIVED SIGNAL FROM THE SERVICE OPERATOR'S TOWER IS REQUIRED TO BE DEMODULATED TO REMOVE THE HIGH FREQUENCY SIGNAL OR THE CARRIER FREQUENCY SIGNAL FROM THE RECEIVED SIGNAL, SO THAT ONLY DIGITAL AUDIO SIGNAL IS LEFT OUT. IN MOBILE PHONES, THIS DIGITAL AUDIO SIGNAL IS THEN CONVERTED TO ANALOG SIGNAL AND AFTER SOME AMPLIFICATION ETC. IS SENT TO THE SPEAKER TO BE HEARD BY THE USER.

BOTH THIS TRANSMITTING (TX) AND RECEIVING (RX) FUNCTIONS ARE REQUIRED TO BE CARRIED OUT IN THE MOBILE PHONE ITSELF AND IS DONE BY WHAT CAN BE CALLED THE RF SECTION OF THE MOBILE.

What is Frequency ?

What is frequency? and what are mobile frequencies?

Mobile phone uses radio waves to communicate with other mobile phones and when you are face to face with radio waves you have to learn about frequencies.

The word frequency is derived from the word frequently which is used with the meaning of circulation of any task repeated with same time period. so if any task is repeated with a same time period you can call its ratio as frequency. In radio waves a the speed of waves going up and down is called frequency and it is measured in Hz(Hertz). if a wave finishes its ten cycles in a second its frequency will be 10 Hz. look at the chart below to learn more about the frequencies.

1 cycle/second = 1Hz

1000 Hz =1Kilo Hertz (1Khz)

1000Khz =1 Mega Hertz (1Mhz)

1000Mhz =1 Giga Hertz (1Ghz)

1000Ghz = 1 Tera hertz (1Thz)

Click this bar to view the full image.

Cell Technology

Geographic areas are divided into a number of slightly overlapping circular "cells." Each cell contains a base station, which is identifiable by its transmitting and receiving antenna located on a tower at the top of a hill or building. The base stations connect to the landline telephone system of the country. The multiple cells combined with low power transmitters allow the same frequencies to be reused with different conversations in different cells within the same city or locale. The primary digital cellphone technologies are TDMA, CDMA and GSM. see cellsite.

 

[JannatLui]

Click this bar to view the full image.

Lets see the first GSM mobile phone how it looks like!
First Cellphone in U.S. Introduced in 1983, this Motorola DynaTAC cost $3,995 and weighed two pounds. (Image courtesy of Motorola, Inc.)

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Mobile phone features

Main article: Mobile phone features Mobile phones often have features beyond sending text messages and making voice callsââ‚ƚ¬Ã¢â‚¬ÂÂÂ�including Internet browsing, music (MP3) playback, personal organizers, e-mail, built-in cameras and camcorders, ringtones, games, radio, Push-to-Talk (PTT), infrared and Bluetooth connectivity, call registers, ability to watch streaming video or download video for later viewing, and serving as a wireless modem for a PC.

Technology

Mobile phone tower Mobile phones and the network they operate under vary significantly from provider to provider, and even from nation to nation. However, all of them communicate through electromagnetic radio waves with a cell site base station, the antennas of which are usually mounted on a tower, pole, or building. The phones have a low-power transceiver that transmits voice and data to the nearest cell sites, usually .5 to 8 miles (0.8 to 13 kilometres) away. When the cellular phone or data device is turned on, it registers with the mobile telephone exchange, or switch, with its unique identifiers, and will then be alerted by the mobile switch when there is an incoming telephone call. The handset constantly listens for the strongest signal being received from the surrounding base stations. As the user moves around the network, the mobile device will "handoff" to various cell sites during calls, or while waiting (idle) between calls it will reselect cell sites. Cell sites have relatively low-power (often only one or two watts) radio transmitters which broadcast their presence and relay communications between the mobile handsets and the switch. The switch in turn connects the call to another subscriber of the same wireless service provider or to the public telephone network, which includes the networks of other wireless carriers. The dialogue between the handset and the cell site is a stream of digital data that includes digitized audio (except for the first generation analog networks). The technology that achieves this depends on the system which the mobile phone operator has adopted. Some technologies include AMPS for analog, and TDMA, CDMA, GSM, GPRS, EV-DO, and UMTS for digital communications. Each network operator has a unique radio frequency band.

 

[JannatLui]

Basic Terms used in nokia flashing


Flash files to download and install
example:

RM-38_v 11.00 (mcusw 4.14) Emea Apac China LTA
this called major version, must be installed first before you can install minor version.
contains MCU, PPM, and CNT.

RM-38_v 11.01 (mcusw 4.14) Emea Apac China LTA
called minor version, can be installed after major version installed, usually contains only PPM and CNT (no MCU, but for some other type, maybe contains MCU newer version also)

another example:
RM-36_v 8.00 (mcusw 5.050407) Euro
for EURO countries

RM-36_v 9.00 (mcusw 5.050440) Apac
for Asia Pacific countries
================================================== ==============
DCT4 tab

1. Checking phone, cables, software version etc.

Flash settings tab
MCU : Micro Control Unit
PPM : Post Programming Memory, contains language
CNT : Content Pack, contains tones, games, etc
ADSP : Advance Digital Signal Processor, flash file for DSP chips
APE : Application Processor Engine

Use INI :
When you thick this, software will detect phone connected type, and “Use INI” files setting when exist in “Product Directory” for choosing flash files.
INI : (*.ini)

This file contains flash files setting for each “Product Code”, including MCU, PPM, CNT, PP (Product Profile), etc.
(Even in 3250, different product code may have different MCU to be flashed).

These files are extracted from firmware/data package that we have installed.
Use this option in order to avoid choosing wrong flash files, example :
- If you don’t know for sure which MCU, PPM, or CNT.
- Choose right PPM for language that you want
- How to choose right CNT that suitable with your PPM


After a Product Code has been chosen automatically, you can change it manually with other Product Code that you want to flash.

Run INI :
After flashing completed, software will upload also Product Profile according INI that has been chosen and flashed.

Product Profile :
This file contains customization for each Product Code, example : GPRS settings, WAP bookmarks, etc..


For Communicator Phone, this file also contains keyboard layout.

Load NFP:
NFP: Nokia File Protected
Data package (MCU, PPM, and CNT) for nokia CDMA phone was compressed as a file :
*.NFP, and it is protected by password.
Thick this option, choose *.NFP, software will extracted it automatically as MCU, PPM, and CNT.


Easy Cable :
It’s a special cable, suitable with pop-up connector for few type phone, ex : 1600, which can be use for flashing. Thick this if you use this kind of cable.

RPL 208 :
PM field number 208 was copied from DATA1/ IMEI flash data.
Software will back up this area as RPL(DATA1 only), that useful for recover flash IMEI if something happen after flash (IMEI ????), or you changed flash IC, you no need to change UEM also if you have back up for this phone. Some type don’t have this field, like 1100, 2300, etc. Make sure your phone can enter Local Mode for this option.

FTD ON:
FTD : Field Test Display / Net Monitor : special menu for DCT4 and DCT4 TIKU that can be activated with flashing, it contains many feature for testing phone and network.

Product Code :
Every Nokia phone has 7digit number that written in the back sticker.
This Product Code will differ phone that sold to one country and another, also phone that sold with customization for an operator, will have different Product Code also.
This number also saved somewhere in PM area.
Thick “Change Product Code” will change Product Code number in PM area after flashing completed.

Factory Set :
Reset all settings to factory default after flash completed.

Manual Flash:
this option will disable software detect the phone model and open his folder when you click on “MCU”, “PPM”, etc, or thick on “Use INI”

Warranty :
When you press *#warranty# or *#92702689#, phone will display some hidden information like Serial Number, Made, etc, including “Life Timer”.
This option after flash will reset “Life Timer” back to zero after flashed.

Unlock:
Initialize sim lock after flash

Erase :
normally, software will erase first some area according Flash Files needed before writing them. If you thick this option, without erase first, software will write the Flash Files that have been chosen. Use this option only if you already have fully erased the phone manually.

Skip AFP :
AFP : After Flash Processing
After flashing completed, software will try to put the phone into Local Mode and read some info about it. This option will disable that process.
Use this only if you know why this process should be skip, example you flash an Erase

File that make the phone dead/ fully erase.
Not all Erase File erase whole part of flash IC, some Erase File only erase some part of flash IC and phone still alives.

Skip MCU ID :
MCU ID is UPP (Universal Phone Processor) recognition, inside flash file, there’s recognition for MCU ID that supported (by that flash file).
Use this option only if you sure that you flash the phone with right flash file, but software give warning that MCU ID is not supported by flash file that have you choose.
Note : usually warning about MCU ID is not supported but right Flash Files has been chosen is caused by bad cable connection. Try restart software, reconnect F-Bus cable from phone, and try again.


For dead phone suspected / possibility hardware problem, if MCU flashing has been completed, continue flashing with PPM only usually will solve.

BT :
Bluetooth IC have own firmware including in MCU file.
You may skip this if you flash the phone with same version, this will save flashing time a little.


But you have to skip this if BT IC is damage, it’s indicated with when you flash a phone and software error in the middle with warning : “Error loading additional loader..”


INF : INFO
Make sure your phone can enter Local or Test mode for this operation.
At the end of this operation, software will detect phone’s Product Code and load Flash Files according it.

If no suitable product code found, you must thick “Manual Flash” and then “Use INI”,software will ask you to “Select Phone Model”.

You can sort it by “Type” or by “Name”, or you can type phone code like RH-12, and all “INI” settings for this phone will be loaded, and can be chosen.


Note : if you don’t find your phone type or name in the list, but you have Data Package installed for this phone, open “nok4models.ini” with Notepad and add it like this
[RM-307]

 

[JannatLui]

CHK : Check
Will check phone hardware condition like
- Relation between UEM (Universal Energy Management - power IC) and UPP (Universal Phone Processor)
- MCU ID / UPP
- Flash IC
- RAM IC
- First 16 bytes
- FAID Calculation

Remember, bad F-Bus cable also make this operation failed !!!
Service:


This button related with “Service Operations” tab

Erase Flash:
Software will try to back up RPL 208 if your phone can enter Local Mode or IMEI Flash Data not corrupted, or RP 208 exist, and then check phone hardware like MCU ID, etc and display Erase Flash Manager.


Flash Chip List:
Below this tab you can choose which IC that you want to erase, and you can modify Erase Address.
Start Address always 0×000000 and End Address always 0xxFFFFF, depends on Flash IC size.

FULL Erase :
Full Erase will erase all Flash IC, including PM (Permanent Memory), & will make SIM Lock Data corrupted.
Make sure that you have back up PM to be uploaded after flash and unlock after this operation.
Click Start Erase to execute this operation.

PM : Permanent Memory, an area in flash IC that wasn’t reached by flash files, means normal flashing shouldn’t change it’s value.
It contains data of RF, EM, Product Code, Security Code, and so many more.
For some type it also contains backup IMEI Flash Data, even phone book and gallery content. PM file can be opened with Notepad or Wordpad.


PM area indicates with :
Field Number 0 - xxx (some type has field numbers <200, some has <255, but newer phone type may have 300>).
Each “Field Number” may has sub “Record Number”
Field Number indicates with : [x]
And Record Number indicates with : x=
If you fully erase a phone, you can upload PM that you have read from another phone which same type, but make sure you have deleted field 5, 120, and 208 from it, ’caused it contains IMEI data.

Repair BT / Repair Bluetooth :
Same with erase PM field 4 index 17 (4:17) that contains BT address.
Some type of Nokia phone save BT address in this field, if this area corrupt or filled with another BT address (maybe caused by upload PM from another phone), & BT can not be switch on, try use this option.
Read Fls ….

Prod Dir :
Change default Flash File detection from C:\Program Files\Nokia\Phoenix to another.
FLASH : start flashing

(Un)Lock:
this button related with “Unlock settings” tab
Init simlock : Initialize SIM Lock, remove Operator SIM Lock restriction
Write SIM file : write file *.SIM that contains SIM Lock settings.
Code Calculator : calculate codes from IMEI number, network code, and ASIC code, for initialize SIM Lock, enter it with type the codes manually with keypad
Read Codes : read phone for IMEI and calculate code for initialize SIM Lock
Auto Lock: after this operation, phone will recognize network code from first SIM Card that inserted to phone, and lock to this network.

Autolock IMSI :
IMSI : International Mobile Subscriber Identity, after this operation, phone will recognize first SIM Card that inserted and lock phone to this SIM.
Lock to Network: enter the network code manually and phone will be lock to this network

Load JAVA :
Upload JAVA application to the phone

MMC Rst:
with special cable adapter, this will reset locked Memory Card

Make INI:
If you have chosen your flash file manually or USE INI, this operation will create your own “INI file” for that type. After this, software will automatically load that flash files after INF pressed.

IMEI tool:
There are 2 IMEI in DCT4 phone:
First is in UEM, also called DATA2, OTP (one time programmable).
Second in flash IC, also called DATA1, not OTP.
If DATA1 get corrupted or not synchronize with DATA2, Watchdog timer will be enabled, phone will be restart after +/- 30 seconds. You will see software says IMEI ?????????

Make ASK: make “ask” file to be calculated become RPL.
This operation is used after you change UEM and want same IMEI number with your phone previously (IMEI at back cover sticker), or you have change flash IC but don’t have back up for this.
Thick “UEM Changed” in order to get DATA2 calculation also,
otherwise ASK will be calculated only for Flash IC / DATA1.

Write RPL (reply) :
Because there are 2 IMEI in DCT4 phone, RPL may contains DATA1 only or DATA1 & DATA2. You can open it with Notepad/Wordpad.
RPL from back up RPL 208 contains only DATA1, will be uploaded to flash IC.
RPL from ASK calculation can be contains 2 data (remember about thick “UEM changed” when make ASK), one will be uploaded to flash IC : DATA1, and the other one will be uploaded to UEM: DATA2.


If you changed UEM, DATA2 will be wrote and become OTP IMEI. No problem if RPL contains 2 data but you did not change UEM, as long as DATA1 and DATA2 are synchronized, phone will be normal.
ASIC : Application Specific Integrated Circuit
class of DCT4 phone:
ASIC 2
ASIC 5 - WD2
ASIC 6 - TIKU BT
ASIC 7
ASIC 11

If you changed UEM and do not want to calculated RPL, you can use “free supplied rpl” that come with software installation, but you have to write RPL with same ASIC to your phone.

IMEI Patch:
this will “patched” IMEI Plain, IMEI that showed by pressing *#06#, with desired IMEI that you want. Patch options only work for DCT4 ASIC2.
And this only work for normal phone, means patch WILL NOT SOLVE problem IMEI ????????? that ’caused by DATA1 corrupted.
If you try this with phone that have problem IMEI ?????????, Watchdog timer will be enabled, and your phone will restart after +/- 30 seconds.

IMEI Save: back up PM 208 as RPL

Unlock : Initialize SIM Lock , needed after write RPL

Read UEM : Read UEM IMEI
If you have phone with IMEI ?????????, check also whether UEM IMEI still good.
If yes, read ASK, calculate ASK to RPL, and write RPL.

 

[JannatLui]

But if UEM IMEI also damage, you have to Change UEM.
Service Operations tab: (use Service button to execute)
Make sure you phone able to enter local and test mode for this service.
If not, check the cable or maybe phone have hardware problem.
Read, Write, and erase PM : look above about PM.

Self Test : test some phone conditions via software.
Always use this feature if your phone has “Contact Service” problem that can not be solve with erasing and flashing.

Disp Test : LCD test.

Upload TUN : RF value for CDMA phone was saved with file named *.tun.
Factory Setting: reset the phone to factory settings

Prod. Manager :
Read or change/write some value that saved in PM area:
- Product code
- HW version : Hardware Version : please be careful edit this for RM-72 - 6230i, ’cause PPM and CNT flash file was different between old and new HW version.
- Order Number
- Production SN

- Manufacture Month : in phone showed by typing *#warranty#

File System Format:
Format User Area of the phone, user data will be lost.
Remember that WD2 have different File System with DCT4 TIKU as example.
WD2 = Symbian EPOC, Drive for User Area : C
DCT4 TIKU : FILE2 , use Format Type : Low Level Format, and type : NAND
So, if software can not detect File System correctly, try making Full Factory before execute this again.

User Code Edit:
Read Security Code which saved at PM filed number 35.
Upload and Read PP:
please look above “Product Profile”

ADC Read :
Analog to Digital Converter : some Self Test about phone battery, charger, etc
Fun Explorer :
About exploring JAVA application in DCT4 phone.
Warranty Reset :
look above about Warranty.
Phone Mode:
(?) read phone status
change phone mode to
Local Mode
Test Mode
Normal Mode

Communication Mode:


F-Bus cable : flasher cable
USB: DKU-2/CA-53, when you connect DCT4 TIKU with this cable, you will be able to make some operation like : make Full factory, Init SIM Lock, etc, but not for flashing.
——————————————————————–
Flashing DCT4 APE phone : 9300, 9500, and 7710:
connect both F-Bus cable and USB cable (DKU-2 CA-53) to phone.
when you make CHK for this phone, System Tray in Windows will give warning about “USB DEVICE NOT RECOGNIZE”, this is normal, and this must be happen.
If you don’t get this warning, you need to check again USB connection to phone, otherwise phone may have hardware problem.
During flashing process windows will install drivers needed for flashing this phone.
================================================== =================

BB5 tab

BB5 phone :
BB : Base Band
Single chip : have only CMT processor. example : 6270, 62880, etc
Dual chip : have two processor, CMT (cellular Mobile telephone) and APE (Application Processor Engine) example : 6630, 6680, N70, etc.

Communication Mode:
F-BUS cable : use only 7 pins cable for flashing with JAF box.
Make sure your phone can enter Local or Test Mode !!!
If not, maybe you need to check your cable, and then modified it, if not suitable with box specification.

1. NEVER EVER try putting 9v battery in F-BUS cable though your cable has this connector !!!

2. Resistance between BSI-GND must be 68k ohms, if less than it, maybe you will find “error sync the phone when make “CHK”

3. Resistance in BSI serial must be 5,1k(5k1) or 7,5k(7k5) ohms. Otherwise your phone can not enter Local / Test Mode.

4. Make sure VPP line from RJ45 connected to RX2 in phone.

Never use cable that connected VPP line in RJ45 with VPP in phone, you will get error something like “Error APE get id”
I don’t give explanation about P-KEY and UFS Box, because newer BB5 phone with RAPIDO processor doesn’t supported by UFS Box.

USB : all (alive) BB5 phone supported by USB flashing, you may use DKU-2 or CA-53, but some types needs DKE-2/mini USB for this operation. make sure your battery fully charged, or charge it with an original charger before start flashing.
When you flash phone and software give error warning “error getting flash id”,
put sim card inside, do not select offline mode, and flash the phone.
Note : make sure you disable all connection in PC Suite (if you installed Nokia PC Suite software in your PC) when using this service.

Dead USB :
Few types of BB5 with single chips supported by “Dead USB flashing”.
Choose flash file manually, connect USB cable to phone, and when software give command to “press the power now”, press switch on/off briefly. In windows systems try, will show “Nokia USB ROM”, and windows will install the driver automatically.
For some types, successfully dead USB flashing will revive the phone, but gallery content will be empty, so you need to flash again with USB as normally.

Downgrade :
This option based on Dejan’s trick to be able to flash a working/normal BB5 phone with lower version.
Maybe not all BB5 supported by this option. So, if you try downgrade and the phone become dead, flash again with latest/highest firmware version.

CRT 308:
PM field number 308 contains SIM Lock data, make sure your phone can enter Local Mode before flash, in order to make successful back up.
If something wrong after flashing process and SIM Lock Data become corrupted, use Write PM and choose this back up to be written to the phone. Your sim lock state will back like before flashing.

CRT BKP: Certificate Back Up, saved as *.RPL.

Skip APE: skip APE flashing.

SX4 Authority :
BB5 phones have protection for writing RF(1 ) and Energy(309, 0×135 in hex) settings in EPROM. Not having those settings in phone, is known as ‘Contact Retailer Problem’, or ‘Security Error’ in Self Test. In order to write those settings phone requires an authorization that only SX4 Smart Card can perform.


As those cards are hard to get, software can use server support for this authorization.
To authorize, connect BB5 phone, and power it on.


Press “SX4 AUTH”. If you have SX4 card connected to PC, software will use it to compute the authorization password and send it to phone.
If you don’t have card, software will connect to server to compute authorization password.
If this process have sucessfuly done, Write PM to the phone without field number 308.
================================================== =============


Update Loaders:
FIA = Flash Identification Address are files that needed for flashing, to identify MCU ID and Flash Files which suitable with phones. If you press this, software will check whether new version from support site exist and replace your flash loaders with new one if you download it.

================================================== =============
Phone phone terminals
VBat - Battery Voltage
BSI - Battery size Indicator
GND - Ground, conductive mass

 

[JannatLui]

How to Repair Mobile Phone Charging Problems Issues

I prepare to used the Nokia Mobile Phone as a set example of this lesson, for Nokia is the most efficient mobile phone to fix for which they provide all source of service manuals and diagrams aside from other mobile phone products on the planet today.
Basically there are many types of charging problems not just in Nokia Handset but all mobile phones products like Samsung,LG,Sony Ericsson, Motorola,iPhone, Blackberry and etc.
like:
Not Charging - When the charger is being plug-in and it shows the word on the display "Not Charging"

Charger Not Supported some sort of like the charger is not compatible with the handset but the problem actually exist on the charging circuit.

No Response - this is what this problem called when even a good and working charger is being plug-in, The handset shows no response or no reaction when the charger is being plug-in.

Fake Charging - The handset is charging by itself even without any charger plug unto it, or the indicator shows that the handset is charging when the charger plug unto it but the battery haven't not charge any voltage or current at all.

Invalid Charger- The handset responds that the charger is invalid and not compatible with the handset.

Those Charging problem issues mentioned above were just common types of faulty charging circuits within any various mobile phone handsets exist before and nowadays.
Experts and Professional Technician have different techniques when it comes to troubleshoot such problems. But mostly all of them start on the basic method on how to find the faulty component or parts within that certain problem.

Now, typically mostly hardware troubleshooters starts within this following methods below.
1. Checking up the charger if the charger is good, weak or being damaged, or try to use other good and working charger to compare if the charging problem still exist.
The picture below is a typical layout of a common mobile phone charger. It converts the AC (Alternating Current)voltage coming from an outlet then convert it into a DC voltage. It has "+" positive and "-" negative polarity. A common mobile phone charger range from 4.5 to 6 volts DC(Direct Current)
Various mobile phone products charger have different types of pin connectors layout and packaging but the operational circuit took inside it almost all the same.

2. Checking up the battery if it is still working or weak and test its Voltage and currents or replace with a good and working one.

3. Checking up the Charging Pin Connector by visualization and see to it for some breakage or some dust and dirt corrosion. Corrosive element such moisture may also cause the problem and see to it that is clean and free of any corrosive objects.
4. Checking up the Charging Terminal Contact Pads if it is free from any dust and dirt and making sure that it is totally clean.

5. Then Proceed to Component Fault Finding Method if found that the earlier mentioned above was all fine but the problem still exist.
In component fault finding method it is also advice to start from the basic test and check up procedures on every components within a certain circuits area. There are so many free and shared solutions scattered away among so many gsm forum communities. Some of them were pictures of jumpers and modification methods and lack of step by step procedure instructions, it is because those certain solutions were belong to all exactly understand the whole circuitry and not for the beginners. That is why only those masters and experts alike only can catch up what was that all about.
But not always happens like that, there are also many experts that always think the benefit of the new learners which he emphasized some step by step procedure on where to start to troubleshoot or test.

 

[JannatLui]

All Beginner Service

Basic Electronics
________________________________________
However a mobile phone is an electronic circuit that is very smart and sophisticated. But the phone can not function when not given the power or voltage (electricity).

Maybe you already feel the benefits of an electric, if you know them from the power characters? Did you ever see the electricity? Did you ever see the electric current? Of course not! Can we feel the benefits of electricity, but electricity can not we see a form of existence, if you are curious about the existence of electric please you touch with your finger to the outlet in your house, hehehe .. shock is not it? Well, with a little experimentation is of course you already can feel the electricity.

Well I will try to introduce practical about electricity, it's a bit difficult to describe an electrical circuit because electricity can not be seen, whereas when we repaired the phone of course we must know the value of the voltage to the range of phones, whether we can know by simply looking at it? No! Needed a measure to find out, for example: avometer, frequency counters, osciloscope, spectrume analizer, etc..

Power source
________________________________________
Initially of course there is the question of what will be the beginning of electricity? Is this universe since the creation of electricity already exists? Yup! Electricity has been around since God created the universe. Obviously you also can feel the power of nature, when the weather was cloudy due to rain, the electricity was caused by lightning, a very large force, it can burn anything that grabbed.

The scientists eventually observed the presence of electronics on electric and natural scientists are finally able to create artificial electricity. With technological developments ultimately the source of electricity can be generated by:

1. Electricity chemical derived from the chemical process stone car battery or accumulator. Electricity is only unidirectional flow only, and is called direct current, abbreviated DC. DC power has a positive polarity (+) and Negative (-), then their use should not be installed upside down.

2. Electricity generated by electricity generators, which are distributed through a transformer and distributed to consumers (users) of electricity. Electricity generated by the generator flows back and forth, and is called the alternating current, abbreviated as AC. AC power is different from the DC power that have unidirectional polarity, polarity AC power will be subject to change, let's say the AC power at home that has electric 220Volt voltage with frequency 50Hz, then the polarity will change as much as 50 times a second. In use, the flow of AC power plug upside down is no problem though.

With the current development of electronics technology, electrical alternating current (AC) can be used as direct current (DC) by using an instrument called a power supply or adapter, the device will be on the phone accesories such as transformers meet charger used to charge battery phone.

Current and voltage
________________________________________
Electric charge that moves us as the electrical current. The magnitude of the electric current can be defined as the amount of cargo that passes through a place of unity of time. An electric current is indicated by the symbol I and the unit is the Ampere, or abbreviated as A. In a circuit, electric current can be defined as a moving electric charge in connection or in components, where electrical current will flow continuously in the system electronics are active. If at one circuit then there is no electric current circuit elektronikapun system will not work.

Charge on the electric current is called voltage. The magnitude of the voltage is defined as the number of electrons contained in the electric charge. Electric voltage is called voltage, unit is the Volt or shortened by V.

Above has been in explaining about the voltage as a measure of the energy of a moving charge in an electric field, where the electric field produces a force propelling charge. This means that the electric field produces an electric current. From this description it is clear that when no voltage (the voltage) there will be no electric current, and vice versa when there is a voltage (the voltage) means that there is an electric field and the possibility of electric current therein. Where a large amount of electrical current depending on the voltage and of materials or components in the electrical voltage ering.

Power
________________________________________
Maybe you never experienced a phone with a fully visible battrey but when the phone call went dead. The incident was caused by the power given battrey not balanced with the demand from mobile phone, it might be possible because battrey who already own cell phone Drop or problematic because there are konslet in the circuit.

To measure watts of electricity used. Watt said first electric power, if the circuit is one ampere to flow through both ends of the pole there is a volt voltage.

Formula: Watts = Volts X Amperes

Example: If a paired mobile phone battery which has a voltage of 3.7 V and 0.7 A current passed (700mA), the phone has been receiving power from the power source for

 

[JannatLui]

The nature of electronic components
________________________________________
Resistors
The function of resistors can be likened to a piece of lumber used to restrain the rapid water flow diselokan / small ditch. By using this board prisoners, then the water flow can be obstructed its flow. This parable can we apply to electrical resistance.

Increasingly wide / big boards that used to hold the water got, the less water flowing, so this incident can be applied in electronics class. The bigger the resistance, the smaller the electric current and voltage through it.

Resistor in an electronic circuit can be enabled to:
1. hold back some electricity to match the needs of an electronic circuit;
2. reduce the voltage as needed by an electronic circuit;
3. dividing the voltage (Volt);
4. working with transistors and capacitors in a circuit to generate high frequency and low frequency.

The amount of value detainees can be expressed in units Ohm or written with the Latin alphabet Ω (omega) and the notation was written with the letter R. The larger the value Ohmnya the greater the resistance.
Physical form is very different resistors on the phone with electrical resistors in general that have a color code to determine the resistance value, the shape is very small phone Resistors (Chip Resistors) and the resistance value is not visible on the body of the resistor, then to know the value of the resistance we need a measuring tool such as AVO -meter, or we can find out through a schematic diagram of the mobile phone.

Capacitor (Capacitor).
________________________________________
Capacitor is a device that has the ability to load (save) the electron-elektor or electricity during the time that is not certain. The ability to store electricity is called the capacity of the condenser (capacitor) capacitor. Electrical energy storage capacitors accompanied by a chemical process; different from that used dimobil accumulator which also stores electric power but suffered a chemical process. Each capacitor has a capacity of electrons and resistance to certain stresses ..


There are two kinds of capacitors, ie capacitors and bipolar nonpolar capacitor. Bipolar capacitor has a negative polarity (-) and positive polarity (+) it should not be inverted bipolar capacitor installation. While nonpolar capacitors is that capacitors have no polarity, then the installation will not be a problem although the inverted position.

The amount of the capacity of the condenser is indicated by the units farad (F) and the notation is written with a capital letter C. In practice usually the units farad (F) is considered far too large, so its use units of farads reduced to:

Abbreviated micro farad? F
Nano farad abbreviated nF
Pico farads abbreviated pF

Comparison of these units are:

1 farad (F) = 1 million? F (? F = mfd)
1 micro-farad (? F) = 1000 nF
1 nano farad (nF) = 1000 pF

Intended use of capacitors in an electronic circuit is in order:

1. As the coupling between the circuit with each other (in a series of Power Supply).
2. As a filter in the series Power Supply.
3. As the generator frequency in the antenna circuit.
4.Menghilangkan bounce (jump the fire) when the plug on the switch.

To determine the value of the capacitor in the phone would be difficult because the value is not written on the capacitor body, unlike the resistor, we can determine its value by using the AVO-meter gauge, the capacitor can not know the value of its capacity, therefore you can only find out through the scheme diagram of the mobile phone.

Know Semiconductor
________________________________________
since the nature of which can deliver electrical current and also withstand the electrical currents known as a substance called half penghantar or semiconductors.
The semiconductors are discussed as follows:
1. Diodes
2. Transistor
3. IC (Intergrated Circuit)






Diodes
________________________________________
Diode is a semiconductor that can only deliver the electric current and the voltage in one direction only and can not reverse the current flow. This diode is usually used for smoothing the flow of the power supply, where the source of AC electricity is then by using the diode currents can be dijaadikan DC current is direct current.

Intended use of diodes in an electronic circuit is in order:
1. Rectifier current and voltage.
2. Securing the current and voltage.
3. Blocker current and voltage.
Transistor
________________________________________
If we look almost in every electronic circuit today many have encountered one or several components of which are small and black color comes with three pieces of leg were each given a name: The base, collector and emitter. Component is called the transistor. Transistors are included also in the types of semiconductor components.

The name is derived from the transfer transistors and resistors, the transfer means transfer or otherwise make changes while the resistor is a material that can not deliver an electrical current.
So the meaning of the transistor is to change the material that can not deliver electricity into penghantar materials or semi penghantar or also known as semiconductor materials.

Intended use of diodes in an electronic circuit is in order:
1. Strengthening (amplifier)
2. Switching (switch)
3. Smoothing the flow, retaining most of the flow, strengthen the flow, generating a high frequency and lace.

IC (Intergrated Circuit)
________________________________________
Circuit Intergrated abbreviated IC is a functioning part of certain aircraft in the process works. Each IC manufacturer has produced a particular use. IC is a unit of the aircraft are usually made of circuits: transistors, resistors, capacitor, and diode. A series of IC usually consists of dozens or even thousands of components bundled into a unit of work processes with a few tens of feet of the terminal until the terminal foot, and then printed with the air vacuum insulating materials such as glass or ceramics in some form.

By the factory IC manufacturing aim is to simplify a series of aircraft, to reduce side effects such as: konsleting, distortion, complexity of a circuit, and to reduce the leaking of a series of planes to protect its rights in law, so that other plants do not easily mimic the production of goods.

To determine whether damage to an IC, can not be done using ordinary measuring instrument, but can you determine a good course and damage the IC by moving to a normal cell phone machine.

IC has the legs of tens of feet of the terminal until the terminal, the shape of the legs of the IC on the phone there are two types namely: 1. which resemble the legs of a millipede, 2. IC BGA

 

[JannatLui]

Signal / Frequency
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Electrical energy (current or waves) can store information, if made in certain vareasi and also a certain time unit (called intensity). Vareasi electrical energy is the term given to the signal (signal). Signals are divided into two types, namely analog and digital. Sine wave is an example of an analog signal. These waves can propagate / or air flowing through the cable, vareasi sine wave signal (intensity)

Time required to complete a wave signals (from A through E), in one second is called frequency (measured in Hertz is abbreviated Hz).

This frequency is a key concept in understanding the Radio Frequency (RF), because RF is frequency-independent. This can be used to distinguish between two different signal frequencies that can be used to divide the frequency of one signal with another signal in accordance with its usefulness.

If we examine the information in the table above, prove that the signal is strongly felt in everyday life. Humans can listen to the signal with frequency 20Hz to 20KHz, this signal is usually called the audio signal. One task is to download the Mobile Transmit audio signal is up to the corners of the world. To be in the form of low frequency sound (audio signal) can be broadcast through a transmitter, must first be modified with the aircraft electrical vibration transmitter in order to become (signal) that a high frequency. This is caused by a low frequency can not be brought up long-distance voice. Only high frequency (HF = High Frequency) or radio frequency (RF = Radio Frequency), which can lead to the corners of the world. The phone can transmit data by RF signals at 800MHz-1900MHz.

Digital Signal
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Another type of electrical signal is a digital signal, which has the same type as a computerized environment. Unlike the sine wave signal (analog signal) that have a gradual difference between the highest point with a low point, the digital signal vareasi occurs between the signals from one another so that there are only two values in the digital signals that are high (logic 1) and Low (Logic 0).

The digital signal mepresestasikan information on patterns of high and low. High and low pattern is used to represent data information on mobile phone technology.

Changing the Analog Signal Digital Signal Manjadi
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Above has been explained briefly about the analog signal and digital signal, the phone system there is a series of analog signal converter and a digital signal. Current phone is a phone that has all-digital, such as the transmission of data for the purposes of: Internet, SMS, MMS, Email, etc.. Data information is data in the form of a digital signal, so the data can be transmitted this information is needed merger with the signal RF (Radio Frequency), for such purpose in requiring conversion of the digital signal into an analog signal or vice versa so that the data information can be in combination with the carrier signal (Carreir Frequency).

In wireless technology, the code in this phone will do the conversion of sound into digital pulses at the transmitting side. On the receiver side will make the conversion from digital back into analog pulses. Coder or Vocoder is sound analyzer with a synthesizer. Vocoder in any digital wireless phone is a chip set called a digital signal processor (DSP). Sound will be modeled and transmitted by the analyzer as the Vocoder. Upon receipt, going to interpresentasikan synthesizer signal and reproducing sound approach in accordance with the original.

Normal sound of music, tone, and all analog signals will convert the phone into electrical waves. These electrical waves in analogikan on sound. Voice circuit will affect the telephone, electronically will continue to represent the sound becomes a continuous electromagnetic wave. Transmission of the analog signal is sometimes affected by distortion. However, within a digital system, these problems have been overcome.

Digital signals are systematically and numeric representation of sound, at every nunasa voice will be perceived as binary digits.
Sound reproduction will be very easy to do by giving the code in the form of numerical digits. There are schemes that contain errors or mistakes to be investigated and corrected so that the digital link in the wireless system will always be intact. To reduce bandwidth, the data signal can be performed data compression or compression.

 

[JannatLui]

What kind of phone and what is the difference PWB with electronic PCB general?
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PWB stands for "printed wired boards, PWB boards are made of fiber glass in which there penghantar wire to connect the many components that will be used as a circuit which in intergrasikan in one module. PWBs and PCBs almost identical function and type, the PCB stands for "Printed Circuit Board", PCB is usually only have one to two layers of lines placed at the front and rear surfaces. In contrast to the PWB phone lines which have many layers, even more than eight layers of highly structured path. Surely you can imagine a machine with so many mobile phones even a very small component size must be connected between the one with the other components into one integrated circuit in one module, when the PWB is very small and limited mobile phone size. In order sizes are not to be a great phone, it takes a path that not only 1-2 layers up to 8 layers but even more, so that these pathways do not require land (area) is very broad.

Damage PWB
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1. Corrosion is often a major cause of damage to the PWB, PWB pathways are very small and thin, due to corrosion terbutus path,
2. Konsleting, electronic short circuit could result in broken lines, as well as a fuse, when an electric current passing through the wire / line exceeds the capacity of the line will break even on fire,
3. Concussion often occurs due to falling or thrown hard phones can lead PWBs be bent, there are pathways in the middle layer is very vulnerable to bending,
4. Sloppy or mistake in doing soldering terminals resulting in broken lines,
5. The use of solder or Hotair too hot or exceed the recommended temperature limits.

 

[JannatLui]

How does Charging Circuit Works from a Battery Charger to charge a Mobile phone Battery

This lesson is also important for charging problem troubleshooting for knowing which parts or components has being used to make a charging circuit. Many mobile phone technicians had been asking me, how does mobile phone charging circuit works?

How does a battery charger can charge a mobile phone battery?
To tell the truth many of them has never heard of this even they already fix thousands of mobile phones in their years of cellphone repair careers." and I am one of them.
I don't know but I know how fix it, its so easy" that's what we've oftenly said.
Well, we all know that all mobile phones are all battery operated handsets that needs to charge the battery so that it will continue working, failure to charge it will result to unable to power up the mobile phone handsets.

Here's a brief explanation of how charging circuit works,
I prepare this simple idea and diminished some electronics technical terms so that everyone without adequate knowledge on electronics technical terms might can catch up with this.

A charging circuit is composed of the following stages or sections.

1. Battery Charger Circuits - Although this is not found on mobile phones PC board circuit and have separate circuit but definitely this is also part of charging circuit; without this, the charging circuit is not complete and will not work completely.
This circuit is all parts and components that being mounted on any mobile phone charger, this is the one that converts AC (Alternating Current)voltage to DC (Direct Current)voltage.
What is AC Voltage? This voltage is a power source that we used in our household appliances to work and operate, this voltage can cause risk of electric shock and very dangerous to humans when being touch.This kind of voltage has an alternate polarity.
What is DC voltage? This voltage is a low level voltage which typically found on any kind of batteries.
This kind of voltage have two polarities, the negative and the positive.

Here's how the battery charger works, the 110 or 220 AC volts coming from the electrical outlet at home or etc. will be converted to a desired DC voltage like 4.5 to 6 volt DC because the phone only accepts and can be operated into small amount of DC voltage.

A DC voltage output of a charger is only an artificial DC voltage, why is that? because only a battery cell can produce a 100% pure DC voltage.

2. Protection Circuit- this circuit is composed of a Fuse, Inductor coil Diode and Capacitors, before the DC voltage reach to the charging voltage control circuits the protection circuit is the one that control and check if that voltage is in exact amount. Let say the desired amount of DC voltage is only 5.6 volts above that point the fuse will be blown out to stop the voltage to flow so that it prevents damaging to another corresponding circuits.
In a protection circuit below of Nokia BB5 mobile phones a diode is the one that measure the amount of voltage from the battery charger, this diode has a reaching point of desired voltage to measure of how much amount of voltage will be allowed to flow within that line, when exceed to that desired point of voltage the diode will then cut it off.

like for example if that diode is being designed that only allows only 7 volts from the battery charger to flow on that line. Now, above that desired voltage let say that the voltage becomes 8 or higher the diode will then be reacts and destruct itself, this is what then so-called shorted component; so that the current will flow directly to ground and will not reach to the following or corresponding circuit. If the diode will cut off or shorted the fuse will tends to blow and totally cut the voltage line. The inductor coil's role is to filter unwanted voltage saturation, it rejects abnormal voltage modulation caused by electrostatic interference.

3. Charger Voltage Control Circuit - This is the stage where the charger voltage and current is being stabilized, amplified, rectified, regulated and other voltage purification process is being held in this area before it feeds to the battery. This kind of circuit commonly being pack in a chips together with another circuits.

A failure of this certain area will result on charging problem status. This area mostly called by most technician as a Charging IC it is because this circuit is inside in a particular IC chips, but eventually this circuit also accompanied by many other circuit types and not exclusive to a certain charging area.

This pictures shows is the next corresponding circuit from the protection circuit area. The voltage from charger is now then feeds into three terminal inputs of the charger voltage control circuits.

in this figure shows after the voltage stabilization and purification process the voltage is now then feeds to the battery terminal.

4. Charging Control Circuit - this is the area where the charging process is being monitored, this is the one that sends information to the application processor to start or stop the charging process. This area is part of Power management circuit, so-called POWER IC by many technicians.

In this picture that there are two terminal signal from the voltage control that sends data to the Charging control circuit, this two data signals will inform to the charging control circuit that a charger voltage is being entered or plug-in. After this charging control circuits receives the data it will then analyze and convert that data into digital signal then sends it to the Application processor.

The application processor which is the brain of all the circuits now then decide if all the data's are in correct or in right information to begin the process,
It always relies on the data that sends by the charging control circuit, then decide all data and completely process it.


Okay now lets take an example and apply this particular method on a mobile phone circuitry component layout, I have here a Nokia N95 board, which is a good way to start with, while we still working on advance training. Now, try to analyze and compare all of those previous picture above and combined them into each corresponding stages or section, in this manner you can build an step by step tracing procedure on how to deal charging problem issues.

In the picture above shows, how and where the voltage flow from a charger voltage source through the entire PC board circuit. This is the the method where you can start and manage how to locate and trace each and every component to find possible problems regarding charging problem issues.

 

[JannatLui]

Understanding how RF circuit Works on Cell Phones

In cell phone repair it is very helpful to understand how the RF circuits works , for this is a big help when
troubleshooting No signal problem issues.
RF stands for radio frequency , this frequency is used to transmit and receive the data signals from a mobile phone.

Here's a brief explanation on how does RF circuit works on mobile phones.
This is for GSM RF circuit only, although the WCDMA circuit and WI-FI circuit have similarity on this but I will try to explain both of it hereafter.

See the block diagram below. Observe how the frequency data signal feeds from a certain parts of an RF circuit design.
A breakdown or failure of each certain part will result to signal loss and the capability to generate, amplify, control , process, send and receive the desired radio frequency during transmission process.

Click this bar to view the full image.

In mobile phones transmission there are two types of operation took place, the receiving operation and the transmitting operation.
In normal mode, RX part is always active in receiving operation the antenna switch is always open its gateway through to the RX circuit, It is always ready to receive and intercepts the radio waves and wait for the desired frequency signal to catch up.
During transmission like making a call or sending a text message the antenna switch will close the gateway of the RX and open the gateway of the TX in order not to interfere the data signal during transmission.
All data that has been receive and before to transmit or send, all this data signals are feeds to the baseband processor.

An explanation of an RF Circuit Parts and what possible problems if a certain part is damaged.

RF Receiver - ( RX radio receiver )
The rf receiver are called RX, this circuit is design to receives, and process the data signals from the airwaves during transmission process. A failure of this circuit will result to unable to receive data signal during transmission.

RF Transmitter - ( TX radio transmitter )
the rf transmitter are called TX which is the one that process, amplify the data signals from a mobile phone .
Once failed to initiate a failure to transmit radio frequency signal, this will result to unable to send data signal during transmission. .

Power amplifier - RF amplifier
The power amplifier is used to amplify, boost up the radio frequency signal before it feeds to the antenna before it thrown over the air waves during transmission. If damaged will result to signal loss.

The Antenna is used to intercepts and thrown the radio radio frequency in the air during transmission
When electricity is "thrown" into the metal of an antenna, the metal reacts to the electricity at an atomic level in the form of a wave.
if damaged or due to a corroded terminal pads, will indicate a show a poor signal or low level frequency signal.

Antenna switch
The antenna switch is used as a gateway that controls and manage the frequency to pass through, it switch the RX frequency signal and TX frequency signal during transmission process. literally the antenna is the signal catcher and likewise the signal thrower. If damaged the gateway to the antenna will be closed and result to network signal indication.

Crystal oscillator
Generates a desired frequency that feeds to the RX and TX circuits. In mobile phones a Voltage controlled Oscillator (VCO) and Voltage Controlled Temperature Compensated Crystal Oscillator (VCTXO) is used in rf circuit.
If damaged the RX and TX will not work and the RF cicuit is at full failure.

SAW filter
Surface Acoustic Wave filter used as an rf synthesizer to purify a desired level of frequency. If damaged result also to no network signal indication.
An example of the RF circuit components layout on a PCB board.

The rf circuit components are often covered with shielding metal case unlike the baseband processor parts which is oftentimes not. This is because frequency is very vulnerable with unwanted radio waves interference and destroys data signals. Using the shielding metal will minimize the radio waves interference.