If there is no service or emergency problem in a smartphone, then how is it repaired?

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Today we will learn in this article that if there is an issue of Network OR No Service in a phone such as emergency, flame network, flame radio signal etc.

First we will know what happens in the network section. When a signal comes to our phone, it has a prx path, which we also call the primary receiving path. One is the drx path which we call divercity path.

When a signal comes to our phone, first of all it goes to the antenna switch of our phone. There is a coupling line inside the antenna switch which decides which band the signal will go.

Any smartphone works on 4G, 2G, 3G, lower band, height band, and medium band.
In any smart phone there are 2 paths, one is rx and one is tx.

In the network section, pa ic is installed, which we call power amplifier. It is different for 4g, 2g, 3g. The phone which has cpu of msm series has wtr installed in it and sdr is installed in sdm series and in which mediatek processor is installed, it has mt61 ices installed. Samsung phones have a transreciever.

Mostly we see that in the problem of no service or low network, if we change the wtr then the problem of low network gets solved. But sometimes even changing wtr does not solve the problem.

The wtr ic also needs a lot of voltages to work, if any voltage is missed then wtr will not work.

If any voltage is missed, then even after changing the wtr, the problem of the network is not solved.
There are many types of voltages such as dig voltage, international 1.8 voltage.

After that it is also an important thing that on which protocol our network section is working.

The new smartphones that are coming nowadays also have apt modulator installed to run pa.

In the earlier smartphones, the input voltage of the pa ic which was installed was bph. But now slowly the android section is changing slowly.

There are two types of bands in the network section, one is TDD band and one is FDD band. There is a time division and there is a frequency division.

So till now we have covered the theoretical part of the problems coming in the network section and now we will know that when you have a network problem in a smartphone then how will you fix it.

If you want to repair network section of a phone then you need setup of borneo. First of all, an antenna wire is used, with the help of which the network enters our phone. We call this path as prx path. then comes rf switch

rf switch for network section in latest smartphones

There are 3 paths in our phone – one is prx. The one through whom the signal comes is called primary receiving. And through which the signal goes, it is called tx, which means transmiting path. The third is the drx path. Means dioercity receiving path.

When we talk to someone, at that time the primary antenna of our phone gets busy. If the internet is to be used at that time, then drx path is used at that time.

So in this way our phone has three paths rx tx and drx(rx, tx and drx)
The IC that the signal goes to first is called antenna switch.

All the smart phones that are coming today have 2g pa connected with the antenna switch.

In the old smartphones, you used to get to see different ICs, but in today’s smartphones you will not get to see the antenna switch.

The first IC installed in today’s smartphone for signal is a mix of 2G pi and antenna switch.

pa ic for network section for smartphones

The antenna switch selects the signal and transfers it to the particular band.

The smartphone has 2G PA and 4G PA IC. SIM works on different bands in different phones. The tx path in our phone through which the signal passes is always PA installed. pa means power amplifier. It amplifies the signal. It is also called pfo. Means power frequency oscillator.

2 pfo can be seen in today’s smartphone. Apart from pfo, our phone has a rf ic which acts as modulation and demodulation in our phone. This ic controls the entire network section. Some phones have 2 rf ic’s. One rf ic is installed to reduce the load of another rf ic.

Apart from this, in the network section, you will find mutual couplers, band pass filters, spdt switches. All of them have different work. If the phone has an ic of msm series, then wtr is installed in it and if sdm series processor is installed then sdr is installed. We can also call it sdr or rf ic. The network ic is also connected with the cpu. bph suply means supply of battry.

PA also needs a BPH supply to function. APT Modulator is installed inside today’s smartphone which is specially installed for PA IC. It is used to provide voltage to the PA IC.

If there is an emergency call problem in our phone, then in this condition we trace the TX path. And if there is no service problem in our phone then in this condition we trace Rx.

The path that goes from the antenna wire inside the phone to the rf switch and from the rf switch to the pa ic is called the Rx path, which means the receiving path, after that when the signal comes out from the pa ic it is called transmitting. Path speaks i.e. tx speaks path.

The PA ic placed next to the rf switch is also called a band pass filter. If there is no service problem in your phone then it may also be bad band pass filter or PA ic.

In most of the phones when there is no service problem then there is RFIC problem or there is voltage problem in it. If it seems, then there is a problem of RFIC in the phone itself.

rf ic can also be called sdr. Sdr is written above the network rf ic. The capacitors around the ic are also called cap.

The capacitors that are placed around the ic have to be checked by putting the multimeter on the continuum mode on them. If value is coming to those capacitors, then it means voltage is coming to them.

If ground is speaking on one side and no value is coming on one side then that capacitor is open, then in this condition IC does not get voltage and if ground is beeping on both sides of capacitor then it means ic in shorting.

When we check the value of a capacitor, it is called GR means ground reading. If the voltage of 1.8 becomes short then your phone will hang on people because this voltage goes everywhere and this voltage is mostly not short.

Where 1P2 is written, it means one point two.

Most of the pm is written on the power ic that is. The rf ic gets its power from the pm ic. Therefore, the capacitors that are installed around the power IC can also be short, so it is necessary to check them too.

Power ic has four sections – LDO , BUK, HK HOUSE KEEPING, AND CDC AUDIO. If there is a problem of NO service in your phone, then by opening the bitmap of the mobile motherboard, the track of the capacitor which is short has to be traced and all the capacitors which are connected in its line have to be checked.

First of all, the large capacitors that are there, they have to be taken out and seen. If the shorting does not come out even after removing them, then after checking the voltage of the line in the diagram, it has to be injected with the same voltage and minor ampere. Due to which the capacitor which will be short, it will get hot and burn automatically.

Here you can also use rogin. This will also let you know which capacitor is short.

Here the voltage has to be taken care of a lot, because the line has a particular voltage. If we give more voltage than that then the IC gets burnt so first the voltage has to be checked in the diagram. The more voltage you have to keep, the more amperes you can keep. It doesn’t matter but voltage can damage the IC.