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Lenovo P780 bad catches NET

15.12.2016 3963

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Certainly, Lenovo p780 pretty interesting Smartphone business series. One of the main advantages among other android smartphones, this is of course a long battery life. The device is capable of work through the week with an average workload. Of course, this is an excellent indicator for today.

 

Now for the cons.

There is one significant disadvantage, poor GSM signal reception.


At one point, either immediately after the purchase, phone pretty bad catches the signal network cellular network from lenovo P780 either very weak or regularly disappears.

Our specialists Cini town constantly confronted with this problem.

Thanks to the large experience lenovo p780 Smartphone repair, we will share with you this very useful information regarding your device.

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Just found two types of breakage of this miracle Smartphone. Divide them on the programming part and component.
The first reason why Lenovo p780 bad catches network, this firmware version selected. Radio (aka SKY radiomolulja amplifier) is a programmable chip, which has its own software. Thus it lends itself to customization, and firmware.
P780 Smartphone comes in two versions. The first is for the Chinese market, second to the European. Now most often model designed for the Chinese market.
The Europeans have problems with signal reception almost does not happen, because it has a completely different radio with firmware that supports all available frequency bands.

Lenovo p780 for the Chinese market has a radio with limited radio frequencies, which in Russia do not use all the base stations of operator. Therefore, on one cellular phone Tower catches good to another is not a steady signal.
This can be partially corrected programmatically. Pick enough for Russia firmware version selected, and the problem will disappear.

Now the second reason why smartphone loses network. The main symptoms of the problem selected lenovo p780 is the almost complete absence of cellular signal. In fact, standing near the relay, 1-2 shows smartphone Division, or simply "cross" signal on the display.

If you are lucky, you can independently determine the nature of the failure.

For this purpose it is enough to remove the back cover, and some under the slots SIM card under the squeeze machine (not so strongly to crush the screen).
At the same time look at the display. Within 3-5 seconds, you will see a complete Division of the indicator of a cellular network.


Note, not every device available this simple metotd diagnosis. In special (quite heavy) cases, the device does not respond to the aperture shamanism.

Now dig deeper into this problem.
So, the culprit as previously wrote the radio component of the cellular network SKY77590 accurate model (SKY77590-11) skyworksinc.


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This is a programmable chip, which provides us with access to a wide range of radio frequencies.

I wrote above "strongly press into casing, the phone began to catch"
Let me explain how this works. Selected component is located just in the very part of the device, where it is compressed. The exact location is pictured below:

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This chip is very fragile and sensitive to high temperatures.

Installation of this chip is made quite a non-standard way than IR soldering station termoprofilju.

When mounting such a sensitive microchips, uses a special low-temperature solder method. This technology is almost non-existent to all usual Tin.
Alloy composition for the installation of the following components:

Lead (32.0 ± 0.5)%

Tin (18.0 ± 0.5)%

Bismuth (50.0 ± 0.5)%

This composition has a melting point just 100 degrees! At this temperature, you can safely install the radiomodule lenovo p780 not overheat it.

Of course, after replacement it is recommended to Flash the appropriate firmware for your region.

Now about the source of the disease)
A common cause of this problem is mechanical impact on the body of the device. As a result of hitting (even on a soft surface such as a rug) soldering microchips vulnerability appears bad contact. This is due to the rather fragile composition for brazing this type. They cannot be put on the usual pojal'nye pastes and compositions. So if its strongly push the module will continue to work, without losses.

Often in warranty repairs Service Centre refuses because of mechanical impact on the chassis (visible signs of impact or damage in the area of the Board).

Let's summarize.

Certainly, our specialists are capable to replace a component selected for your Smartphone and get it back to normal life.
Very ask you carefully take the device, do not shed, buy silicone bumper or other type of protective cover. This significantly extends the lifespan of your mobile Assistant.

Always happy to answer any and all questions! Write an article!

Demekhin Sergey Lvovich