Before we go any further about repairing mobile phones, of course, you must first understand the working principle of mobile phones, in order to facilitate the analysis of damage to the phone. This time will be discussed in outline and in general, due to the development of today's mobile technology is always changing.
Command processing center input / output.
Command input.
Each time you do a command to the phone, eg texting, playing games, changing phone settings, voice recording, photos, and more. All of the above command is a command from the user to the mobile phone, which can pass through an order like: 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 data contained in the operating system flash IC. IC flash will store the input data when ordered by the CPU, RAM, while IC will accept data from the CPU for a while.
Output command.
CPU will give the canal commands of the command input, the command of the CPU is very universal in the overall mobile phone navigation system for example: giving commands to display graphical information on the LCD, giving orders to the UI (vibrator, buzzer, LED), gives orders to the power supply for voltage retribution, and others.
Power Supply
Power up / down (On / Off)
The process to turn the mobile phone is not the same as the usual electronic circuits such as TV radio etc.. At almost the same phone system with computer, where the process does not turn on or turn off the power by removing the power supply connection. In the actual computer system if given the power, the system is functioning just switched off, when in analogy to human beings in a state of sleep, in which the system will be ready whenever given the command to activate all systems. By because it's when the phone has been on battery then attach the battery voltage will go directly to the IC power supply, while at the same power supply IC will provide voltage to the processor. SW circuit On / Off phone you can see in the picture diawah this.
SW circuit On / Off Mobile
Voltage distribution
The circuit on the phone there are many subsystems, where each sub-system has a voltage supply needs vary and on any voltage when the system will be given when needed. Power on the phone first to be given by the battery, the voltage from battrey will continue to power supply IC, the IC power supply voltage supplylah all will be provided depending on needs.
Charging the battery
The process of charging the battery on the phone is very meticulous, which will be regulated charging system computerized. Battery voltage will be detect by IC power supply and CPU, when battery is fully charged then the phone will reject the filling of the transformer charger. Charging system is processed by charging IC.
Data transmission of information
Basically, the transmission system in a communication system, 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 emission (transmitter) serves as the data transmission of voice information or alphanumeric data, graphics and network registration process.
The registration process network
Initialization
The first time you make a phone call to a process called initialization. This happens when you first turn on your phone. You will get a connection from sell terdekekat site, then the mobile network will perform account or your membership is still active or not, the call will be processed further.
Inspection frequency list
Your phone will do a list of frequencies that exist in your SIM. Inspection covers carrie frequency flow quality, then search Broadcash Control Channel or BCCH. Each BCCH will transmit 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 the data instead of radio frequencies.
Identification information
Base station or Broadcash Control Center will continue sending the identification information on the site sell. Identity is Carreier wireless network itself, the current location area code, and frequency yag used, as well as information about the surrounding cells. All this information can be used to find out if your phone is on and in need of services. 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.
Examination Broadcash Control Control Channel
Radio frequency phone will do a bradcash control channel, where your phone will send a signal to double check your master if the signal is still within reach. The phone will scan as radio throughout the BCCH frequency list one by one and check the signal reception. Measurements will be performed at each level of the channel. Cell site will send a strong signal to your phone. Meanwhile in broadcash control channel which is a mobile monitor did ase station data stream from the so-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.
Transmitting information data
voice data signal processing, graphics, alphanumeric.
While mobile users are conducting communication, then the wave sound signal generated from mobile users will travel in the air. Gelobang voice signal will be received by the microphone is converted into electromagnetic waves. And will be continued to the audio processor to be strengthened and processed.
If mobile phone users do sms, then type the command at the keyboard by mobile phone users will be processed by the CPU (Central Proccesor Units)
change the digital signal into an analog signal (D / A Converter).
In this section the data signal information is converted into the form of an analog signal. Because the RF section is still using an analog signal while the shape of the main character in the form of a digital processor. 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.
Mixing the data signal with the carrier signal.
Signal data information will be sent to the base station, surely there must be a signal that carries the data information. Therefore the information data signal will be mixed with the carrier signal by the RF processor. Carrier signal on GSM technology has a frequency range of 900-1900 MHz, the wave is 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.Once the information data signal is mixed with the carrier signal will then proceed to the section is called the Modulation .
Strengthening the final
Signal data information that has been mixed with the carrier signal will be received by the base station, while the distance to the base station the phone far enough. Then the signal has to be really strong to be able to be received by the base station. Then the signal must be amplified by the PA Power Amplyfier. When strengthening the end of the section delivery is not functioning properly then the phone will not be able to register the network to the operator, this is caused because the base station can not receive the data signal information from mobile phones.
Distribution Transmission lines
Once confirmed then the signal will be continued to the antenna switch is connected to the antenna. Antenna switches can be in analogy such as airports, where on the transmission of data information on mobile phones, there are two pathways, namely receiving and transmitting. So without the antenna switch signal with the received signal to be emitted will collide with each other, because there is only GSM technology, there is one lane with a system called TDMA.
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 transmission, the signal is weak or strong depending on the quality antennanya.
Receiving data information.
Receiving data from the base station
Signal emitted by the base station information will be received in advance by phone antenna. And then be forwarded to the antenna switch for forwarded to the LNA.
The division of a transmission line
In order for transmitting signals with signal reception does not crash, it will be divided by the first signal transmission antenna switch.
Strengthening early
Signal in order to be well received by the RF signal emitted by the base station will be strengthened first by the LNA (Low Noise Amplyfier). LNA not only functioned as a reinforcement, but can be functioned as cutting noise (sigh).
Separation of the carrier signal with the information signal
Signals generated by the LNA still mixed with the carrier signal, in order to be processed by the DSP (Digital signal proccersor) the information data signal to be separated first by the RF processor. This system is called the demodulation.
changes 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 while the shape of the main character in the form of a digital processor. 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 part of the main processor (CPU). When the data signal information is voice then will proceed to the audio amplifier.
Strengthening the end of the voice signal
When the data signal information is voice data, it will be amplified by the audio amplifier terlabih first before continuing to the speakers. Audio signal will be converted into electromagnetic waves, will in order to connect to the speakers of these electromagnetic signals into sound signals that propagate in the air that can be heard by the human ear.
