B. Power IC
Power IC Is an IC that serves as a supplier of electricity to other ICs in the phone. This IC does not generate its own electricity, if traced, the electricity distributed by this IC comes from the main battery of the phone. Therefore if the connection from battery to IC is disconnected, the phone will be totally dead. It’s easy to know quickly whether Power IC is working or not. How, check the use of electric current from the phone using Ampere meter, or turn on the phone with a power supply that already has Ampere meters in it. If the Power IC is not working at all, current usage is not aliased zero amperes.
C. Crystal 19.2 Mhz
This 19.2 Mhz crystal is often underestimated by the technicians. In fact, if these components do not work, the result is very fatal. The phone will be totally dead. Serves as the heart of the 19.2 MHz oscillator circuit that produces a 19.2 MHz Clock signal. If this frequency signal shifts beyond its tolerance limit, the RF circuit on the phone will not work. The phone will not be able to enter the network.
D. CPU IC + CPU RAM
CPU IC + CPU RAM is the center of the settings of every part of the phone. Functions a lot, among them is to set the process of turning on the phone, audio process, battery charging process, data signal processing, and others. If the IC is damaged or not soldered well, will cause total death, hang, can not read SIM card, no sound, no signal, and so forth. Uniquely, in this phone and some other phones, CPU and IC RAM installed by stacked one other dang. IC installation method in this way is often referred to as PoP (Package on Package). The CPU is mounted on the PCB while the RAM IC is mounted on top of the CPU IC. Many advantages of this kind of installation method, primarily to save space, so the phone can be made smaller and compact. But of course there are drawbacks, if collided, it is easy to get problems between the two ICs are stacked. Also in the process of replacing one of the ICs, much needed extra precision. Otherwise, the stacked IC becomes corrupted.
E. Flexible Charger Connector
Flexible Charger Connector Is a place to connect the main PCB to the PCB where the charger connector
F. RF IC
RF IC Functions to process RF signal. RF signal from antenna, will be processed into signal RX I / Q. And also the signal from the base band of the TX signal I / Q will be modulated into the RF signal to be transmitted. If there is interference with this IC, can lead to weak signal, no signal, can not radiate, difficult to exit mask, signal down, and also dead total. When there is a problem with the signal, IC is one of the most problematic components. In addition to being the most active component of the RF part, the main reason for the problem is the connection of this IC to the PCB. Packaged on a BGA basis, this IC has many legs made of lead, making it easy to crack and become bad connect. In the repair must be ensured the connection. Be careful this IC is quite sensitive, wrong handling will result in total death.
G. RF Oscillator
RF Oscillator clock Be careful with this component, although its size is relatively small, but its function is very central. In addition to causing total death, can also cause no signal damage. Basically, this Oscillator works to produce a sine wave with Radio frequency. This frequency should be absolutely right. When the oscillator is damaged, will cause total death, can not get a signal, signal up, interference at the time of the phone, and also the phone likes to die.
H. Power Amplifier
Power Amplifier or often also called final amplifier serves to amplify the modulated TxRF signal, so have enough power to reach the nearest BTS. This component is relatively easily damaged. If there is damage will disrupt the transmitter system on the phone. Disruptions that can be seen by the user is the phone can not call in and out, difficult to call, no signal at all, wasteful batteries, and others.
This IC is very easily damaged. So it deserves a priority when fixing the signal problem on the phone. It’s good, technician friends make sure in advance that the receiver (Rx) of the phone in good condition, before checking PA(Power Amplifier) IC .
I. EMI LCD Filter
EMI LCD FilterUseful for protecting CPU IC from static electricity that may enter from the LCD connector. If the LCD blank, the picture or text is not clear, do not directly accuse the damaged LCD. Very likely damage to this component.
J. Antenna Connector
Antenna Connector Is a place to connect the main antenna. If there is a bad connection on this connector, the quality of GSM incoming signal will decrease drastically, the user’s complaint in this case is ‘weak signal’
K. DC Audio Regulator IC
It works to generate a certain voltage for the Audio IC. As an active component, the audio IC obviously needs a supply voltage. The working voltage comes from the audio regulator component of this IC. If this IC is not working the audio IC will not work. Symptoms that arise is no sound from the speakers, headsets, or sounds that would be sent through the microphone.
L. Audio IC Function:
As the incoming voice signal processor of the RF IC, then amplified and forwarded to the speaker, amplify the sound vibration that has been changed first by the mic into electrical vibration and then forwarded to the RF IC, running commands from the CPU. In the Audio IC there is also PCM (Pulse Code Module) and EEPROM that serves to read the signal code coming from the operator to be adjusted with the IMEI phone. Besides it also serves to store data that is permanent like imei, phone code, etc.
As described in the first Post, to make improvements to the phone required an understanding of the functions and types of components. Aims to facilitate damage analysis on damaged mobile phones.