Why is the cell phone not working. Diagnostics and elimination of malfunctions in the repair of cell phones.

Our diagnostics are free.

In our opinion, the service center is not only an organization that directly deals with the repair of mobile devices. We believe that the service center should also be an adviser for its customers and potential customers. On the pages of our site you will be convinced of this. Now the topic of our story is the following problem situations that mobile phone owners may face:

the phone does not turn on;
Bluetooth does not turn on on the phone;
phone screen does not turn on.

Several facts prompted us to consider these problems. Firstly, such incidents, unfortunately, occur quite often, and this is noted by the number of such calls to our service center. Secondly, this can happen with absolutely every tool. cellular communication, little depends on the manufacturer, one day Nokia, Motorola, Samsung, Sony Ericsson, Siemens, and other devices may not turn on trademarks. Thirdly, often not knowing how to behave at the moment of trouble, the owners, instead of helping their phone, harm it, significantly worsening its condition. In our article, we will not only consider why the cell phone does not turn on, but we will also give some advice, we will tell you if the phone does not turn on what to do.

So, if you notice that your phone has stopped turning on, read our publication, we are sure that you will find a way to solve the problem that has arisen, and also calm down, the worries will disappear, as you will have information about the causes, you will know what to fix the state of your mobile assistant is possible. We propose to analyze each type of such unpleasant incidents separately, focusing on its technical features and on our proposals for repairs in each case. As already briefly noted, it is very important that the actions of the owner of the device that has come into a faulty state be prompt, correct, and, most importantly, not harmful.

Let's start by considering the situation when, after turning off, it does not turn on mobile phone. Recommendations from experts in such cases are as follows:

first charge the mobile phone, for this leaving it on charge for a day. If this does not help, you can talk about the failure of the battery;
remember if moisture could be the cause (perhaps bathing took place a few days or weeks ago). If the device took “water procedures”, then you better contact the specialists of a reliable service center, because the “floater” will need diagnostics, and then drying, cleaning - procedures that can only be performed at the proper level using special equipment; - the fault may be a failure software. We will not advise something in this area, since there is a possibility that you will harm your means of communication. It is better to immediately contact the service center;
another option is the failure of one of the microcircuits, which led to inoperability.

Also, if you do not know why the phone does not turn on, we advise you to familiarize yourself with some useful information below. After trying all the described methods, you can find out the cause of the problem:

First, make sure the battery is fully charged. If it happens that the battery is completely discharged, then sometimes after connecting the charger, 30 minutes pass (this is the maximum), and only then the battery charging icon appears on the screen;
second, try to press the on/off button for about 10 seconds to turn it on telephone set;
thirdly, if there is a memory card in the mobile phone, you should remove it, then try turning it on again. If this helped, and the mobile phone worked, you may need to purchase new map memory.

Next, let's talk about the reasons that the phone turns on and immediately turns off (or, as our customers often say, turns off on its own). Sometimes this phenomenon provokes a bad battery or a malfunction in the connection between the battery and telephone contacts. But most often, if the phone turns on and off, then this indicates mechanical damage (drops or bumps) that have taken place, which adversely affected the condition of the printed circuit board or other internal elements. You can check this at home if you bend your phone quite a lot with your hands: turning it off after such actions of yours or “freezing” will confirm that the problem is in printed circuit board or other internals. You won’t be able to help further on your own, you will have to go to a service center, where they will offer to make hardware repairs, which will be the solution to the problem. It may also be that the spontaneous shutdown is due to a failure of the telephone software. This happens quite rarely, but it still happens, so this factor should be taken into account when understanding the reasons why it turns off and on nokia phone(or LG, Motorola, Siemens, Samsung, Sony Ericsson…). It is best to fix a software breakdown in a service center. And in general, there are many more reasons for this behavior of a mobile phone, but it makes no sense to do this, since troubleshooting can only be done in a professional workshop specializing in the repair of cellular communications.

If it periodically happens that your Samsung phone does not turn on (or representatives of the Nokia, Motorola, Siemens, Sony Ericsson trademarks turn on “once again”), then most likely you will need a hardware repair by a specialist. But still, we note that the fault is most often the power button (this is the greatest measure for products from Nokia and Sony Ericsson). If so, then you will have to replace the defective part. The second reason is the ingress of water, which could have happened both in the recent past and a few months ago. After all, when there was moisture getting under the case, inside the cellular communication device, then the drying procedure, as well as cleaning, was necessary. If this was not done, then it is quite possible to assume that this is why there was a partial or complete inoperability. Also, if the Motorola phone (or another manufacturer) does not turn on, or if it does not do this every time, then mechanical damage may also be the cause of this behavior. You can determine this if you come to the service center, where diagnostics will be made, after which the workshop employee will name the true cause of the breakdown, no longer assuming, but stating.

Next, let's talk about those cases when the phone charges but does not turn on. If, according to the indicators of the indicator, charging is in progress, but in fact after it, for example, the Nokia phone does not turn on at all, or the charge lasts for several minutes, then you cannot do without contacting the service center. Since various kinds of malfunctions can lead to such a result, ranging from software failure to the failure of certain electronic components.

Unfortunately, it often happens that the phone does not turn on after the update, we suggest discussing the features and such troubles. First, I would like to note that, perhaps, nothing terrible happened. Just using the Update Service sometimes drains the battery. If the mobile phone does not turn on after the update, we recommend connecting it to a charger and charging the battery. Post-update problems can also show up on the screen that the update is complete (“Upgrade completed”), but your cellular device refuses to perform any noticeable action, and you are wondering what to do? We advise you to remove the battery, disconnect all cables, then put the battery back in its place and press the power button. In most cases, this works, but if not, you already know what to do, come to us, our specialists will sort out the situation and fix all the malfunctions.

Let's continue consideration of the given problem on an example of the mobile devices made by the Nokia company. So, our further advice will touch on what to do if your device “died” during the update, if after this procedure your Nokia phone does not turn on. First, remember that the Nokia screen usually goes blank during the update. But still, it is possible that the Nokia Software Update application simply lost contact with your favorite phone, which led to the screen freezing. In this case, you should:

disconnect your Nokia device from the USB cable you are using and remove the battery for about 5 seconds;
reinstall the battery, then press the power key and hold it down for 1 second;
reconnect the updated Nokia to the USB cable and wait 10 seconds;
Try the Nokia Software Update application again.

If your Nokia is still not responding, you can try to restore it by formatting, for this you need:

press and hold down the call (call) and asterisk buttons;
press the power button and hold it pressed for 1 second;
continue to hold down the 3, bell and star keys until the start tone is heard.

If you still do not receive a response, take your Nokia mobile to a service center that works with products from the manufacturer in question.

Next, the conversation will focus on what to do if the phone screen does not turn on, does not show, or stripes appear on it. The fault may be a defect in the display itself, therefore, it needs to be replaced. By the way, we can replace any display nokia models, Samsung, Motorola. Sony Ericsson, Siemens... If you own a clamshell or slider, then a faulty cable may be the culprit. You can also change it with us, we install only original spare parts, high-quality and reliable. We should not forget about the defects that have arisen as a result of exposure to moisture. If this is the case, then a thorough diagnosis and cleaning will be required, and sometimes a more serious repair.

A lot has been said already, we hope you were able to find useful information for yourself. But still, I would like to summarize our story, and also once again remind you that with us you will find a solution to the following problem situations:

the phone is dead and will not turn on;
the phone turns on and freezes;
the phone fell and does not turn on;
and many other similar incidents.

I would also like to remind you that our service center works with equipment from different manufacturers, in particular, we eliminate the following faults:

phone does not turn on Sony Ericsson or Nokia;
Samsung or Motorola phone does not turn on;
LG phone does not turn on;
Siemens phone does not turn on.

Contact us if your Sony Ericsson phone (or other brands we have repeatedly mentioned) does not turn on, and you will not regret it in any way. After all, our employees are experts. highly qualified who have undergone special training, who follow the repair recommendations of manufacturing companies. Our diagnostic equipment allows workers to make a 100% correct "diagnosis" of non-powered mobile devices. And, as you know, the correct definition of a breakdown contributes to its faster, more effective elimination. Also, the advantage of cooperation with us in the issue of restoring the full functioning of cellular communications is that only spare parts supplied directly from the manufacturer are used. We can talk a lot, but the best argument will be the fulfillment of your order. We have no doubt that once you use our services, you will no longer look for any other service center.

The cell phone has been splashed with water or the phone itself has fallen into the water.

The first thing to do is to disconnect the battery from the phone. Then try to somehow dry the device with a hairdryer, put it on the battery for the night, put it in a warm place for a couple of days, etc. Perhaps after that the phone will work without problems. Although, as practice shows, the lion's share of phones that come in for repairs were previously exposed to water (rusty spots inside, oxidation, raids, etc. indicate this), and who knows for what reason the phone really failed this time. In any case, it can be argued that it was the water that once got there that played no small “role”
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise, you may experience partial or complete inoperability of the phone. I emphasize that it is possible, but not required. But the process of oxidation (rusting) can take quite a long time, and it is impossible to say how the phone will behave the next day or a month later. The more time has passed since the moment of moisture ingress, the less likely it is that the phone will restore its full functionality in the event of a breakdown.

The cell phone does not catch the network.

The first thing you need to pay attention to is whether the phone shows at least some level of reception on the display. If it does, then the network you have chosen may not support your carrier. To do this, go to the "SETTINGS" menu and select the "AUTOMATIC" network search mode. If it didn’t work out at the same time, try to select your network manually, in the same menu.
The next reason may be your SIM card:
• Expired
• SIM card is out of order
If all of the above does not help, then the problems lie in the phone itself. There are many of them: from software failure to failure of the electronic components of the phone.

SMS not sent from mobile phone.

The most common reason for this is the number of the Short Message Center (SMS center) is incorrectly specified, or it is completely missing. In fact, short messages (SMS) are sent to this number, and the mobile operator redirects further your short messages (SMS) to the recipient's number. Each mobile operator has its own SMS center number. Get this number from your mobile operator.
• The number of the Short Message Center (SMS center) is entered in the cell phone's SETTINGS submenu, in the MESSAGES menu.
Also, short messages (SMS) may be blocked by a mobile operator due to non-payment or other reason.

Does not show cell phone display.

One of the reasons may be the defect of the display itself. Its replacement is required.
If we are talking about a "clamshell" or "slider" phone, then in this case the cable may be the reason. This is a flexible part with conductors that connects one part of the phone to another. It is possible that one or more of these conductors is damaged. The loop needs to be replaced.
We can also talk about a defect that arose after moisture got inside the phone. In this case, a thorough diagnosis and cleaning is required, and possibly a more serious repair.

Stripes on a cell phone screen.

If the display itself is damaged, this is the worst, although this may not be visible visually. The display needs to be replaced.
If the phone is of the "clamshell" or "slider" type, this may be due to damage to the cable - the transitional part from one half of the phone to the other.
This can also happen if moisture gets inside the phone.
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise....(described above).

The mobile phone keyboard does not work or does not work completely.

Most often this is due to moisture ingress. In the best case, it is required to clean it from oxidation, unless, of course, it arose only under the keyboard.
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).
It can also happen after a fall or a blow. In this case, a complete soldering of the phone is required.
Such an element of the phone as a processor is fully responsible for the keyboard. So the keyboard may not work due to its failure.

The call in the mobile phone wheezes or does not work at all.

The phone is in "silent mode": in this case, the ringer is disabled
switch off " silent mode” (on many devices you need to press and hold the “#” button)

Alert mode selected "vibrate only" or "silent"
in the "sound settings" menu, turn on the sound notification

Moisture got into the phone
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).

The call is out of order.
In clamshell or slider phones, the reason for this may be a damaged cable. This is a flexible part with conductors that connects one part of the phone to another. One or more of these conductors on the cable is damaged. The loop needs to be replaced.

The speaker does not work: you are heard, but you are not.

It may seem ridiculous, but there are very common cases when a phone is brought to a service center with the volume turned down to a minimum and complain that nothing is heard. In this case, it is enough to turn up the volume during the conversation.
If we are talking about a clamshell or slider phone, then the malfunction may lie in the cable. This is a flexible part with conductors that connects one part of the phone to another. One or more conductors on the cable responsible for sound are damaged. The loop needs to be replaced.
This is also possible due to mechanical damage.
The rest of the reasons lie inside the phone.

The microphone in the mobile phone does not work: you hear, but you - No.

Usually the problem lies in the microphone. If during the diagnostic process it turns out that the microphone has “flew”, it needs to be changed
If we are talking about a phone with an active flip (folding part with a microphone), then the reason may be the microphone cable - the transitional part between the flip and the phone
Moisture that has once got into the phone can lead to such consequences.
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).
Several elements are responsible for the operation of the audio channel in the phone. Find out which one is out of order.
It can also be caused by a software glitch.

Cell phone is not charging.

The reason may lie in the charger for the phone. A simple example to find out is to find someone you know Charger from the same model. But I repeat: exactly the same!!! If you insert a charger from another brand into the phone, provided that the connector fits, then the phone itself may fail. For example, many Samsung and LG phones have the same charging port. But they have different chargers due to the fact that power is supplied to different pins of the charging connector. And, if you connect the LG charger to Samsung phone, most likely the processor of the phone will fail. Its replacement is an expensive process. And it happens that it is completely impossible to repair the phone after that.
The next reason may be in the phone's charging connector. For example: it happens that you start to move the charger connector in the phone's charging socket, and the indication starts to show that the phone is charging. In this case, the phone charging connector needs to be replaced.
If the charging indicator shows that the phone is charging, but in reality, after charging, the phone either does not turn on, or the charge is enough for half a call. There can be many reasons: from software failure to failure of the electronic components of the phone.

Mobile reboots (restarts).

Here you can talk about several things, for example, software failure.
It happens that the reason for the reboot is a failed phone power amplifier. When turned on, it starts draining ***** too much current, the phone turns off and on again. And it seems to us that the device is rebooting.
Another reason may be mechanical damage to the printed circuit board of the phone or its elements. This usually happens after a fall or a blow. Sometimes this can be checked by bending the phone with your hands (quite a lot): if the phone turned off after that or “frozen”, then this is the reason.
Also, one of the reasons may be the battery of the phone.

The cell phone drains quickly.

This most often happens due to poor battery. You can check it at home empirically - ask to exchange the battery for one day with a friend who has the same phone.
This can happen because of the charger - the phone does not charge. As a rule, this happens when using a "non-native" charger, in other words - "Chinese".
If the phone dies when you make a call, and you just charged it, the problem may be in the phone's power amplifier (transmitter). Often this happens due to the fall of the phone.
If we are talking about smartphones, then they can be quickly discharged due to a virus like "Carib". This virus does one simple action - it constantly turns on Bluetooth, which drains the battery. The virus is transmitted "by airborne droplets", that is, via Bluetooth. The easiest way to protect yourself is to set the Bluetooth access settings to "NOT FOR EVERYONE". And it will not damage the installed antivirus, since it is impossible to remove the virus without loss. Removal will result in complete cleaning phone memory.
There are many possibilities for why this might happen.

The cell phone does not see the SIM card or writes a SIM card error message.

One of the reasons may be your SIM card:
• Expired
• Account ran out of funds
• SIM card is out of order

The easiest way to check is to insert another card into your phone. For the purity of the experiment, it is better to use the card of the same operator as yours.
Perhaps the phone is “locked” (encoded) for a specific operator, and you are trying to insert a “foreign” (other operator) card. In this case, use the SIM card of the operator under which the phone is “locked”.
It happens that the contacts of the SIM card or the contacts of the SIM receiver on the phone are dirty or oxidized. Try an ordinary eraser to wipe all their contacts.
It often happens that the contacts of the SIM card do not reach the contacts of the SIM receiver. Try to fix this by placing a piece of paper folded 3-4 times between the SIM card and the battery. This is possible if the device is designed in such a way that there is a SIM card under the battery, and it is not located in a special card reader. An example is the Siemens SL45, A50, A52, A60 models.
Nokia N71 is an interesting case: oddly enough, the phone may not see the SIM card due to poor battery contact with the phone. Try cleaning the center contact on the battery and the corresponding contact on the phone with an eraser. It may be the same with other Nokia models. Inexplicable but the fact!
Nokia 8800 does not see the SIM card intermittently: we have encountered this case many times. And also a strange case - try to replace the battery. Due to a bad battery, it may not see the sim card.

The joystick in the mobile phone does not work.

If the joystick is bad, but works, then the point is most likely in the joystick itself. It is best to replace it and not bother with its repair. As practice shows, repaired joysticks do not last long.
If the joystick does not work at all, the joystick may again be the culprit. But there are cases, as with non-working buttons: the reason lies inside the phone. Such an element of the phone as a processor is fully responsible for the keyboard and joystick. So both the keyboard and the joystick may not work due to their failure.

The cell phone asks for a "phone code".

Usually, it is enough to enter this code, and access to the phone will be open. But this is not always the case. If after entering the correct code, I repeat - the correct one, access was not opened, then it means that there was a failure in the software. The phone software needs to be changed.
You neither sleep nor spirit know about this code, that is, you personally did not enter it there, in this case, referring to the phone's instructions can help. There you can find the standard phone code that was entered at the factory and enter it into the phone.

The cell phone does not connect to the computer.

The first reason may be a computer, a program or settings in the computer itself.
If the phone is connected to the computer using a cable, then both the cable itself and the connector in the phone may be to blame. Try cleaning the connector pins on your phone.
If all of the above is in order, then start checking the connection settings on your phone.

Cell phone turned off and won't turn on

Try to start charging your phone by leaving it on charge for a day.
Perhaps the reason is some moisture that has once got into it. Diagnostics required.
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).
Often the culprit is a software glitch.
One of the microcircuits could fail, which, for obvious reasons, led to inoperability up to “not turning on”.
It is possible that the battery has failed.

The cell phone turns on "once".

Usually the power button is to blame (especially in Nokia and Sony - Ericsson phones). Its replacement is required.
The second reason is that water once got into the phone.
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).
The fault may still be in mechanical damage.

The cell phone turns itself off - self-shutdown.

Often the reason for this is a bad battery or a poor connection between the contacts on the battery and the phone.
The second, most common cause is mechanical damage to the printed circuit board of the phone or its elements. This usually happens after a fall or a blow. Sometimes this can be checked by bending the phone with your hands (quite a lot): if the phone turned off after that or “frozen”, then this is the reason.
Also, it happens that self-shutdown occurs due to software failure. This happens less often, but it also happens.

Vibrating call does not work on a cell phone.

Moisture may have been the culprit
In all cases of moisture getting under the phone case, it is necessary to dry and clean the device. Otherwise... (described above).
It is possible that the vibration motor itself has failed - it needs to be replaced
If we are talking about a clamshell phone, then often the vibration motor is located next to the display at the top of the phone. The reason for the inoperability of the vibrating call in this case may be a loop. This is a flexible part with conductors that connects one part of the phone to another. Consequently, one or more of these vibro conductors has been damaged. The loop needs to be replaced.

The phone only works with one operator.

Such phones are called - "locked under the operator." The data of a particular operator, under which it is “locked”, is sewn into their program code, and when you try to insert a “foreign” SIM card, the device “swears”. There are only two options here: either use the SIM card of this particular operator, or unlock it.

Cell phone hangs up.

A common cause is mechanical damage to the printed circuit board of the phone or its elements. This usually happens after a fall or a blow. Sometimes this can be checked by bending the phone with your hands (quite a lot): if the phone turned off or “frozen”, then this is the reason.
Also, the cause may be a software failure (software). For example, in modern Nokia phones, it looks like this: after switching on, the word NOKIA appears on the screen and the phone “freezes”, that is, it does not react to anything and does not show signs of life. You have to disconnect the battery to make the image disappear.

Quick phone test for nutrition.

We take the Digital Power Supply. We set 4 volts and connect it instead of the battery.
If the current consumption is above 300 mA, then the power breakdown, see the power supply.
If the protection works, then this means the transmitter is out of order, we change the transmitter.
If nothing consumes, then everything is fine.
If, when PWR is pressed, the consumption is more than 100mA, then one of the stabilizers (five-legged) has come out.
If the current is not more than 30mA, then the software does not work.

Mobile malfunction - typical malfunctions and repairs cell phones available.

Like any complex technique, cell phones often fail during active use. This can happen for a variety of reasons, such as factory marriage, long term operation or careless handling by the owner of the phone. The main reasons for the breakdown are frequent falls, water getting into the phone, bathing the phone in water (fell into the river, got into the washing machine), non-compliance with the operating rules specific model or simple negligence, because many phone models are very fragile in handling. For example, clamshell models often break due to negligence.

If the phone breaks down, the owner starts looking for a place to repair cell phones and comes to the service center to the master repairman for help. And in this situation, the master must quickly and competently conduct an initial diagnosis of a cell phone and repair it if necessary.

In general, fault diagnosis is a kind of art, based primarily on a deep understanding of the principles of operation of the device. Without this, it is impossible to master the art of repair to perfection. Below we give a general approach in the repair procedure using the example of a phone Nokia 6020, and training on, as well as your patience, accuracy and attentiveness, will allow you to gain experience and polish your skills.

Mobile phone malfunctions can be divided into three types:
- mechanical damage;
- failure of electronic components;
- incorrect operation of the phone software.

Mechanical damage

Mechanical damage is detected visual inspection, including with the help of optical devices - . It should be noted that even small external damages that appear after the phone is hit or dropped can result in the formation of microcracks in some contact track, which, in turn, leads to the phone's complete inoperability. Most often, microcircuits of transmitters and antenna switches assembled on a ceramic base suffer from impacts.

Failure of electronic components

Universal test

The failure of electronic components is usually accompanied by a change in the current consumed by the phone. There are so-called quick tests, which are based on measuring the current consumed. Some manufacturers, such as Nokia, technical manuals give algorithms for such tests. However, as a result of the test, we can only talk about the probability of a malfunction of one or another element, although this probability can be quite high. For testing, you need to remove the battery and connect an external power source with a voltage of 4.2 V to the battery contacts of the phone, it is desirable that it be a stabilized power source with an indication of the output current.

The phone is off.

The current consumed by the turned off phone is 0. In phones, two microcircuits are connected directly to the battery - a power amplifier (transmitter) and a power controller. A faulty power controller draws approximately 300 - 400 mA, and a faulty power amplifier can cause a short circuit ( short circuit). That is, if the phone, when connected to a power source, the phone immediately starts to consume 300-400 mA (we do not press the power button), then most likely the power controller in the phone is faulty and needs to be replaced, in this model the power controller is called UEM. And if, when connected, the power source stabilizes and stops supplying current to the phone, and the multimeter in the dialing mode shows low resistance and “beeps”, then you can remove the power amplifier and check the phone is turned on. If the phone turns on, then install a new power amplifier.

The initial current is 0.

We press the power button. If the current is still 0, then either the switch, or the switching circuit, or the power controller is faulty. You can check this circuit by disassembling the phone.

Next, you should visually inspect the power button. Then you need to measure the voltage on it, if there is voltage on it (about 4 volts) and when you press it, it drops to zero, then the switching circuit is working. In this case, the UEM power controller is most likely defective or not soldered.

You can solder the UEM power controller using a hot air gun from soldering station type . Let's put a little no-clean on the microcircuit.

Set the hot air gun to a temperature of about 280°C. Gently warm up the microcircuit.

After warming up, it is necessary to clean the board with a board cleaner spray, for example,

After that, the phone will either turn on, or may behave as indicated below.

If the current is approximately 50 mA when the button is pressed and disappears until the button is released, then the program in the FLASH memory is faulty.

In this case, the phone must be reprogrammed. To do this, we need a UFS programmer with HWK and an f-bus cable to connect the phone to the programmer.

We also need firmware for this phone with latest version.

We connect the programmer to the computer, install the latest drivers for it, latest version programs for this programmer, perform an update for it (if required). Open the DCTxBB5 program, click on the button Connect, thus we will connect the program with the box (programmer). Next, select the platform, in our case it is DCT-4 and select the desired model.

Next, click on the button Check to check the contact of the cable with the phone, and also send the bootloader to the processor. If the processor and flash memory are working, then we will see information about this in the program window, if an error is displayed instead of information, then we probably need to replace or restore the installation of the processor and / or flash memory chip.

If information about the processor and flash memory is displayed, then let's try to flash the phone now. We select the firmware files of the main program code(MCU), a language pack (PPM), in our case with the Russian language (which is indicated by the letter “K” at the end of the file name) and content (CNT) (of course, also with the Russian language). MCU, PPM and CNT versions must match.

If errors occurred during the firmware process, then hardware repair of the processor part and further flashing are necessary.

At the end of the firmware process, we try to turn on our phone. If the result is negative, then hardware repair and finer diagnostics are required.

Conclusion

In this article, we talked about the very first steps in surface diagnosis and repair of phones. For deeper diagnostics, additional equipment is required, electrical circuits ability to read and understand them. This knowledge can be obtained from us at. Also in the network of stores "PROFI" you can always find the necessary spare parts for cellular Nokia phones, Samsung. Sony Ericsson, Motorola and other manufacturers.

Everyone needs a mobile phone today. Staying in touch, you can always be sure that relatives, friends and loved ones will always be able to get through to you, and you can get help from them. However, it also happens that the phone suddenly fails, and you find yourself in a difficult situation when there is no way to transfer to someone important information, provide assistance and even just call a taxi.

That is why it is necessary to remember that the phone, as a rule, breaks down in regular situations that can be easily prevented, as a result of which cell phone repair service center will be a much rarer occurrence for you.

If you are in the habit of throwing your phone into your bag, then think about how much damage all the items in your bag can do to it. Business card holder, notepad, keys, pens, hairbrush - these are the simple items that can harm the phone.

Such breakdowns are common, but the main reason for repairing a phone is its fall. If your phone has fallen, then its case or display may break, and the internal components may break, which will lead to their forced replacement, as a result of which you will definitely need nokia repair, the service center will only help. A common problem among mobile phone users is moisture getting into the phone. You need to quickly remove the battery from the device. Then you need to dry your phone. It may turn on, but in the future this event may make itself felt by a breakdown in the future. And if the phone does not turn on, then it is better to contact the service center, where they will help you solve your breakdown.

If your phone does not find the network, then first you need to check the status of the SIM card. It's possible that it just expired. But if everything is fine with the SIM card, then the problem lies in the phone itself. There may be problems with the firmware or some parts of the phone. In this case, too, you should not solve the problem yourself, but you should contact the experts.

Display broken? The solution to the problem is simple - replace the old display with a new one. Such a breakdown is typical for phones after a fall and also after mechanical damage. But such a breakdown could be caused by moisture that got into the phone or a problem with the firmware of your device.

Damage to the display or cable may result in image distortion or streaks on the display of your mobile device. It could also fail the controller on the board. Such breakdowns also cannot be solved by yourself.

Problems with the speaker and microphone occur in the phone after these parts are out of order. Another reason is a damaged cable. Breakdown is typical for those phones that have a threat of chafing the cable.

If the device is not charging, then it is worth checking the battery and the health of the charger. If everything is OK, then the charging connector may be the cause. In this case, the connector is changed. But if the phone continues to refuse to charge, then it is worth diagnosing it in more detail in service center to solve the problem.

If the phone freezes or does something uncharacteristic to it, then most likely this is a software failure of the device. It just needs to be updated. Other causes are damage and falls. But moisture could also get into your phone.

In case of any breakdowns of the phone, it is better to immediately contact the service, where it will be diagnosed and the breakdown will be fixed. On your own, you can worsen the condition of the device. Therefore, a quick visit to specialists is a solution to a phone breakdown.

DO NOT ATTEMPT TO REPAIR YOUR PHONE YOURSELF, THIS MAY CAUSE MORE SERIOUS DAMAGE AND MAY CAUSE MORE REPAIR COSTS!

The keyboard does not work on the phone, the device does not respond to key presses. The phone turns on, but it is impossible to enter the menu, dial a number, make or answer a call. The reason can be both the failure of electronic components, and simple contamination of the contact pads. The defect is eliminated by cleaning the phone, or by replacing the controller. Sometimes components fail due to moisture getting into the phone. In this case, they are replaced with serviceable ones. The phone has been exposed to liquid or has been soaked in water. First of all, remove the battery from the phone. For full information on how to save your phone, you can find out by calling us.

The most common breakdowns after liquid gets inside the phone:

1. Stop working function keys, keyboard, joystick phone.

2. The phone does not boot, the display is filled with white.

3. The phone does not respond to the charger and does not turn on.

4. The device's speaker or microphone stops working.

5. Uneven backlighting of the screen, stains are visible, the front glass is fogged up.

Never connect any accessories or charger to your phone. In any of these cases, you urgently need to seek help from the nearest workshop. The sooner you apply, the more likely it is that the phone will be restored, the less it will cost to repair it.

No online registration.

In the event that the phone has stopped “seeing” the operator’s network or registering in it (there is no inscription with the operator’s name, you first need to make sure that it’s not the SIM card in the phone. Try inserting a known working SIM card, it is possible that it has been damaged, expired, or out of order. If the situation does not change with a working SIM card from another device, then the problem lies precisely in the cell phone. The reason for the failure can be a variety of malfunctions: internal mechanical damage, to a failure in the operation of the phone's control program. Such malfunctions can be diagnosed and repaired by a master in our cell phone repair workshop.

Does not show the cell phone display, the screen does not show or is filled with white.

If the phone display is blank or blank, the most common solution to the problem is to replace it. Often the display fails after the phone falls on a hard surface or other mechanical impact, such as impact or bending, in which case it may be in colored stains. Sometimes the cause of a breakdown can be a cable from the board to the display or other failed electronic components. If the display glows white or artifacts appear on it.
, which may disappear and reappear, then the cause of the breakdown is most likely the cable connecting the main board and the display module. Often cables deteriorate on phones where the display is on the mobile part of the phone, on the so-called "sliders" and "clamshell phones". malfunctions of this kind are successfully diagnosed and eliminated by qualified craftsmen who have special equipment and tools. The exact cause of the breakdown will be called to you in our service center after the diagnosis.

The image on the display is in color bands or is missing in parts.

The screen may be in bright color or white bands. One of the most common causes of such defects may be a cable malfunction (see paragraph above). On different phones The same problem can manifest itself in different ways. The most prone to such breakdowns are “sliders” and “clamshell phones”, where the connecting cable is subject to mechanical wear as a result of setting parts of the phone in motion, which, in principle, is provided for by the design, but all parts have ultimate strength. However, the cause of such malfunctions can be moisture that has got inside or the failure of electronic components. The master will be able to name the reason only after a complete diagnosis of the device.

The speaker in the cell phone does not work, the subscriber is not heard or the ringing tone is not heard.

When you do not hear the interlocutor or the call signal, or you hear it very quietly and increasing the volume level does not help, then the most likely cause of the phone's defect is a failed speaker. Its replacement is a fairly standard procedure and does not require a lot of time. In the presence of spare parts, in some cases repairs can be carried out directly by contacting our workshop. However, the cause of such a defect can be a failed connecting cable connecting the phone board and the speaker. This failure can be considered typical for mobile phones with moving parts of the case, because. in the process of using them, the cable can “fray” or the material from it gets tired and starts to break, a crack appears in the conductors, breaking the contact. The malfunction is not complex and the repair of such defects does not take much time.

The subscriber does not hear you or hears very badly.

Make sure that your phone and the subscriber's phone are outside a closed room or near a window, and the signal level from the operator is not the last value on the screen, but at least 2-3 bars. If you are not heard by the interlocutors during the conversation even when you are in an open space, then most likely the matter is in the failed microphone of the phone. Often a mobile phone microphone malfunction is caused by moisture getting into the microphone. It needs to be replaced at a service center. Replacing the microphone is not a difficult repair and is done quickly enough. However, there may be phones with similar symptoms, in which the microphone may be working, and the reason may lie in a malfunction of the connecting cable. In this case, the loop is replaced with a new one.

Cell phone does not turn on or charge.

If the mobile phone has stopped charging the battery, then first you should check the health of the charger and its connectors. Most often, it is it that fails, because. the number of chargers in use and not produced at branded factories is very large. You can check the device by replacing it with a known good one, or by connecting a phone with a similar connector to the charger being diagnosed. If the charger is working, then the problem may be in the phone's charging connector. More precisely, in its wear or loss of contact with the main board. It often happens that by pressing the charging connector more tightly or by changing the angle of its inclination, staggering, it is possible to achieve an indication of the charging process for a while. In this case, you should contact the service center, which will replace the connector.

If the charging indicator shows that the phone is charging, but in fact this does not happen, then the service center will identify the exact cause of the malfunction after the diagnosis. There are a lot of reasons for such a breakdown, one of them is a faulty battery or charge controller. If the phone does not respond to charging and does not turn on, the battery may have been heavily discharged (phone storage) - leave the phone on charge for a few minutes. If everything is in order, the phone should turn on. If this does not happen, try turning on the phone with a known charged battery. In the case when this does not help, it is the phone that is faulty. Be sure to remove the battery from the phone and contact the repair shop, only qualified diagnostics will reveal the cause of the breakdown. The fault may be a software failure, a malfunction of the battery controller, or mechanical damage to the phone. Please contact the service center.

The mobile phone cannot fully turn on or boot up, freezes, “buggy”.

If your phone from some point started to work with long delays when navigating in the menu, “freezes” and is buggy (failures in sending and saving SMS, viewing or listening to records, games, calling phone book) or periodically reboots, then, most likely, the matter is a software failure and you need to update the software, (“reflash”) the cell phone. Another reason for such failures and failures can be mechanical damage to the phone board or its elements. This usually happens after water gets into the phone, serious blows, falls. The reason for the failure can only be determined in the conditions of the service center.

The joystick, some or all buttons do not work.

These defects often appear either due to mechanical damage to the cell phone or due to water getting into the phone. In the first case, most likely, you will have to change the board with the keyboard or the cable leading to the keyboard. In the second case, washing and drying faulty parts or replacing them will help. Diagnostics in the service center will determine the exact cause of the malfunction of the mobile device.

The phone asks for a code.

If your phone refuses to turn on or perform any actions without entering the security code, phone code, then most likely you need to enter the code specified in the instructions for the device. If you changed the security code and forgot it, or you could not find it in the description, then updating the phone software will help you. Be careful, when you change or update the software, all data that was in the device (contacts, SMS messages, photos, etc.) is erased.

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