Information that may be useful in self-diagnosis and troubleshooting

iPhone 5S diagnostics

At the end of 2017, the most frequently repaired iPhone is Apple iPhone 5S. It displaces the four and the usual five from the market, since its performance is still enough to “pull” the latest iOS, it is small in size (compared to 6, 7) and very easy to maintain

Phone diagnostics

In this article we will not talk about simple causes of failure - broken screens, old swollen batteries and stuck buttons; the purpose of this article is to shed some light on the diagnostics of the iP5S motherboard. All instructions provided below are designed for technicians and services who are just beginning to understand component repair of motherboards. If you are not involved in phone repair, then this article is not for you, you need. If there is a client phone in front of you, and this is your first iPhone on which you decided to try yourself as an advanced repairman, then put it aside, go to Avito and buy a phone for experiments. SYSTEM-SERVICE company is not responsible for your actions after reading this article.

What you need to have before you start

1. Multimeter with thin sharp probes (Mastech have proven themselves well)
2. A set of screwdrivers (pentalob, small cross, large cross for “double-deck” bolts that secure the board) (screwdriver set on Ali)
3. Several tweezers of different calibers (set of tweezers on Ali)
4. Soldering station with hair dryer (as well as flux and solder in a coil), the cheapest option is YaXun 878D.
5. Laboratory power supply min. 0-5V 1A (any power supply unit within one thousand five hundred rubles in your supplier store)
6. Understanding of basic circuitry (boost, buck converters, properties of basic electronics, basic electrical laws)

So, in front of you is a brick that shows no signs of life

We remove the largest shield from the back of the phone board using a hair dryer, trying to remove it quickly and not overheat the microcircuits under it. Be sure to remove all black protective stickers from the shields and around the connectors (touch, display, battery, etc.) before heating with a hairdryer, otherwise they will melt and when you need to remove them, you will rip small capacitors and resistors off the board.

The shield was removed find U7(further in the article the generally accepted names of microcircuits will be used, if you don’t have the slightest idea what U7 is, then look at the diagram), under U7 (on the side opposite the TOSHIBA memory chip) there are 8 capacitors, ring them, then they go in a row 7 inductors, and under them a number of capacitors - power filters for the processor, SoC and GPU. All these system components are located on a single A7 chip and are powered by U7. Orient the board so that the row of the aforementioned capacitors is closest to you, and the TOSHIBA memory chip is on the opposite side. Ring the capacitors using a diode or ordinary ringer. There should be no ringing; ringing means a short circuit on one of the power lines. If at this stage you suspect that you have found a short circuit, determine which power line it is - SoC, GPU or CPU. Using the diagram, find the capacitors sitting on this bus. If the phone is after water, then, for sure, some containers are closed. Use a hairdryer to remove the most “suspicious” capacitors if the phone is drowned. If the phone stops turning on by itself and there are no traces of water, then only luck and experience will help you identify the failed capacitor.

If there were no problems with the wiring of the power supply circuits of the A7 chip, look for the short circuit elsewhere.

All capacitors were removed, but the short circuit remained

For drowned people, the short may be inside the BGA matrix under the chip. To start, place flux on the side of the chip and blow it under the chip. Now your task will be to warm up the space under the chip so that the flux will corrode and remove possible corrosion. Don't heat the chip to melting point and wait for it to float. Heat until the flux burns out or evaporates. After the board has cooled, wash off the remaining flux and check the result. Did not help? Remove the chip if you have not done this before, good advice: do not skimp on the temperature, set the hair dryer to 400-450 and minimal air flow, heat the target chip and “push” it with tweezers to feel the moment when it floats on the solder. Remove with either tweezers or a vacuum remover. Then either reball (we do not recommend) or bet a new one. In any case, clean the contact pads well with braid and change the flux several times. There should be no problems with installing the microcircuit; it will “float” just as well.

There is no closure, but no start either

Hook up the battery and the bottom cable, start the board by connecting the charging cable, measure the voltage on the SoC, CPU, GPU power supply. Without a connected display, there should be no power to the GPU; power to the CPU and SoC should be around 1 volt. If there is no short circuit and one of these supplies is missing, consider replacing U7. All voltages are present, the board warms up a little, boots, but there is no picture? Measure the voltage on the backlight capacitor (in the diagram S131), if it is not there, then you either missed a short circuit, or the diode or backlight driver has failed. They are for replacement. Changing the backlight driver is quite unpleasant; there is a memory chip nearby that should not be overheated. Place a heavy coin on it or wrap it with thermal tape + foil so that the air from a hot hair dryer hits it as little as possible. The capacitor and backlight driver are common culprits for the lack of pictures on the 5S. There is high voltage (20V) and when water gets in, this place burns out first.

Turned on but won't charge

On the 5S, the TRISTAR chip is to blame. Change it. Of course, the article assumes that you have already tried to change the battery and the lower cable.

In addition to the tristar, transistor Q2 (a four-legged microcircuit) can create problems with charging; it can be replaced; in some cases, a jumper is thrown there.

Sometimes it is difficult for iPhone owners to determine the problem on their own, especially if the problem is not visually detectable. It often happens that an external microphone does not work. Phone owners do not pay attention to its malfunction for several months, since they hardly use it. During diagnostics, specialists even check those functions of the iPhone and iPad that the average user is not aware of.

What should you check when diagnosing an iPhone or iPad?

In order to conduct a quality diagnosis, you need to keep the following list in front of you and follow it from start to finish so as not to miss anything.

- Checking the physical buttons and the “vibrate” button on the iPhone. This includes the Home button (it should work 10 times out of 10 presses), Power, volume control and silent mode. All buttons should respond with a response from the phone and a characteristic click. When you turn on the silent mode, a vibration signal should be triggered.

- iPhone network check. With the SIM inserted, all you need to do is make a call. With this call, you can immediately check the following two points.

- Check microphones and speakers and iPhone headset. This is easy to do when calling. It is enough to have two phones with you. You need to call from one to the other, bring them to your left and right ears and count to 10, pausing between words. All numbers should sound clear on both phones. This way you can check the internal microphone and speaker. To check the external microphone and speaker, you need to turn on the speakerphone and repeat the test. Also at this point you can check the headphones, three buttons and microphone on the headset.

-Checking the iPhone proximity sensor. When making a call, you need to cover the top of the screen with your hand. This is a command for the phone to turn off the display and touchscreen so that the speakerphone does not turn on during a conversation.

- Wi-Fi If the iPhone 10 steps from the router shows 1-2 bars on the Wi-Fi network indicator, this means that the Wi-Fi module and antenna are working normally.

- Checking the camera and flash. To check, you need to photograph a dark plane with a flash. In photographs, the flash should spread strictly from the center of the photograph and not illuminate any one corner. When taking a close-up shot (3-4 cm), the camera should focus on its own. Don't forget about the front camera. In the resulting photographs, you need to look to see if there are any dark spots or stripes.

- Checking the iPhone display (screen) In order to make sure that the screen is of high quality and well installed, it is enough, with the screen turned on (preferably with a dark background at full brightness), to press on the glass next to the speaker and next to the Home button. You don't need to press hard, light pressure is enough. If spots appear on the screen when pressing, this means that the screen is either of poor quality or poorly installed. Also, the display should not have dead pixels (bright colored dots that are clearly visible when turning the iPhone on and off)

- Checking the iPhone charging/sync connector Judging by the name of the connector, its task is to charge and connect the iPhone to iTunes. If, when connected to USB, the computer reacts with a characteristic sound, and the phone is charged at least 1%, the test can be considered successful. In iPhone models up to and including 4S, this connector also transmits an analog audio signal. This means that it should stream music when connected to a docking station with speakers. You also need to visually check the connector for debris and dust inside.

How to do a full diagnostic of iPhone, iPad and Mac?

If you buy a phone second-hand, it would be best for you to make an appointment with the seller at our service center and ask our specialists to check it. During the inspection, our specialists, in addition to basic diagnostics, will also check moisture sensors and the presence of solder marks on the motherboard of the iPhone, iPad, Mac. These are very important factors that affect the condition and cost of the device.
Also, during diagnostics, our specialists clean the phone, including such hard-to-reach places as the speaker, connectors, microphones, etc.

This manual is also intended for iPhone Xs and Xr

What if you need to check the entire smartphone? What if it’s not an iPhone, but an Android? There is an option!

The TestM application will help you check all components of your smartphone and identify most common faults. Moreover, no special knowledge is required. Even a child can handle it.

Why diagnose your smartphone?

TestM is a new and very promising application for testing smartphones on iOS (App Store) or Android (Google Play).
Such an application should have appeared a long time ago. Minor faults and the growing secondary market for smartphones required a diagnostic tool that was fast and accessible to the masses. That’s exactly what TestM became.

With TestM you can:

• check the functionality of your smartphone components and see what needs to be fixed;
• when buying an iPhone secondhand, ask the seller for a full TestM report to see the condition of the phone before purchasing;
• Make a full report before selling your iPhone so the buyer can see the condition of the phone.

Typically, the device is sent to a service center for this work. I did this a hundred times when suddenly I began to hear the interlocutor worse, the connection became unstable, GPS or some sensors stopped working.


And service is an eternal lottery: a rare master will miss the opportunity to earn money. The smartphone will be repaired even if there is no fault. Although, believe me, this is not the worst thing that can happen. And TestM will help save time, money and nerves.

How TestM replaces a service center

At first glance, it may seem that there are hundreds of applications for checking and testing smartphones. More often, they access smartphone components directly, using information from them without processing. Is there a signal from the microphone? Great, it works. Are the sensors sending data? Efficient, everything is fine.


At best, Antutu or Geekbench will help you find out if your smartphone is overheating or if there are dead pixels on the screen. They will also show the general configuration and performance in parrots. In the best case (if you have root rights), they will show a direct set of data from the sensors, without processing. Which only a professional service worker can understand.

TestM conducts full testing of smartphone components. Moreover, without requiring tools, additional equipment or root. You don't even need to understand modern technology. Any modern smartphone running iOS or Android can be tested with TestM.


The overall performance of the device and system performance are assessed at the first launch. In addition to them, TestM offers a choice of 2 sets of tests: quick and full. A quick test determines the performance of the main components:

• screen,
• conversational dynamics,
• proximity sensor and accelerometer,
• cameras,
• microphone.

The full set of test exercises for smartphones in TestM can do much more. You can check all types of sensors, network interfaces (including GPS), the operation of hardware keys and the vibration motor, camera components and the operation of the charger.


I recommend doing the full one - more checks, higher reliability.

No knowledge needed - TestM will tell you what to do

Another thing is how TestM checks the performance of a smartphone and its components. While conventional test utilities check hardware software responses to a test request, the TestM set of tests checks the actual operation of smartphone components. You look at the screen and follow the instructions.


Testing the screen requires swiping your finger across the entire surface. In this case, a touch on the touchscreen is registered, the operation of the sensors is recorded, and the cameras form an image on the screen and undergo their testing.


The next test asks you to listen to numbers played through the main speaker and enter them into a special form. Finally, the third part of the test starts playback of monaural frequencies, which are simultaneously recorded by the microphone of the device under test.


TestM then analyzes the received information and compares it with a database of the results of its own testing of similar devices carried out by the developers. They contain the accuracy of the sensors, the volume of the speakers, the sensitivity of the sensors and microphones.


Even photographs are analyzed by TestM using special algorithms: is there any unnecessary noise, are there any dead pixels in the image?


A separate and very big plus of this application is checking the touchscreen and 3D Touch operation. Without this utility, checking their operation is not an easy task, oh not an easy one.

The utility displays the final results in a visually understandable graphical report on the website, in an application, or in the form of a picture that can be attached to an ad or sent to the buyer.


The report is clear and simple: everything is fine with these smartphone components, others require careful study, and still others show poor quality performance.

After passing the test, the utility will tell you the addresses of the nearest service centers and show their location on the map.

What TestM is missing

I conducted a full test of the smartphone and analyzed the quality of the smartphone test using TestM. As expected, almost all tests allow us to accurately confirm the serviceability of the device components.


You still have to use a little ingenuity. TestM does not use flash or light sensor when testing the camera, so it must be tested in good lighting. Flash and sensors are separate tests, separation is necessary for accuracy.


A similar situation can arise when testing interfaces: it is worth checking whether they are enabled. And listen to the prompts correctly, otherwise nothing will work!

One more note: the “volume” of the battery in TestM is estimated approximately. For an accurate check, several charge-discharge cycles are needed.

Instead of conclusions. The app everyone needs

Sean Tell, co-founder of TestM, believes that this utility will help simplify the sale and exchange of smartphones in the secondary market:

“Field selling platforms such as eBay often allow sellers to hide the shortcomings of their smartphones and sell them above the market price. TestM is an excellent verification and reporting tool for buyers and sellers."

Is your iPhone malfunctioning? Has he stopped responding to requests? Can't hear your interlocutor? Started to turn off? And you don't know what to do? Immediately take it to our APPLE-SAPPHIRE service center so that our technicians can diagnose it and determine the cause of the breakdown.

iPhone diagnostics is a procedure that helps a specialist accurately determine the malfunction of the device. After it is completed, the specialist will be able to give the exact timing and cost of repairs. Only a professional should be responsible for this process. By trying to troubleshoot your device using third-party programs, you expose your smartphone to various threats.

iPhone diagnostics is a mandatory and important procedure that largely determines the efficiency and success of repairs. Of course, in most cases the user can describe what is not working and what the probable causes of the malfunction may be. But it often happens that he has no idea what the problem might be. At the same time, it is simply impossible to do without diagnosing all the components of the device.

Our APPLE-SAPPHIRE service center offers not only fast and professional diagnostics, but also repair of original components with a long warranty.

Any repair services, original spare parts, affordable prices - you can find everything with us. Thanks to a favorable and balanced set of qualities, our workshop is considered one of the best in Moscow.

How is iPhone diagnostics and subsequent repairs carried out?

Knowing about us, you won’t have to look for long to find where to get your iPhone repaired. At the same time, you don’t have to go to the service yourself - you can use our courier delivery.

Before properly repairing the device, our technician performs the following operations:

• Device diagnostics, which takes place in 2 stages. First, diagnostics of the connector, control and charging buttons is carried out. If they malfunction, we turn on the gadget. If it does not turn on, we send the smartphone for diagnostics. The next stage is to check the serviceability of each individual component and motherboard. The system checks such parameters as the operation of Wi-Fi and GSM antennas, power consumption, camera backlight and display. We perform all these operations free of charge and take no more than 30 minutes.
• Once the type of fault has been determined, we inform the client why the smartphone is broken and what is needed to fix it, including the cost and repair time. Repair times of varying complexity may vary, but in any case we have a minimum:

— replace the display in 30 minutes. It will take exactly the same amount of time to install the buttons and touchscreen.

- remove the old ones and install new cables, connectors, speakers, etc. – the operation is much more complicated, which can take 40 minutes;

— change the SIM reader or housing part — from 50 minutes;

— antenna module, controllers, microcircuits – from 2 hours;

— cleaning and restoring a smartphone after mechanical damage or moisture is the most difficult operation (after all, our technicians will have to check all components, many of which require replacement), which may require 3 hours of work.

• After repairs, we perform testing and provide a warranty and components.
• Our tariffs are the most affordable in Moscow. Just look at our price list or call the operator - and you can see for yourself.

Why iPhone diagnostics Is it better to order from us?

1. Courier delivery of the device

Each of our clients can use the courier delivery service. The technician will be able to come to your office or home and deliver the smartphone to our workshop.

1. Free diagnostics

Pre-repair diagnostics, which is carried out before starting work, is carried out using software, special tools and equipment. The accuracy and efficiency of the results are guaranteed.

1. Guarantees

As mentioned above, we are ready to provide guarantees for all work and components. We carry out all work that falls under the warranty period free of charge.

You contact us in some way or simply bring the device to the service center. If you call, we will be happy to advise you.

Contacts of our service center are on a special page: .

2. Reception of the device

Now you have already come to our service center. The secretary receives the device, records the malfunction according to your words, enters the data into the computer, issues the necessary document from the reception and transfers the device to the technician in the service area for diagnostics.

The secretary will, if possible, offer you tea or coffee.

3. Diagnostics

In our service center, diagnostics are carried out completely free of charge for any of your decisions. Even if you pick up the device after diagnostics, we will not take money from you.

During diagnostics, the technician checks the condition of the device and finds out the cause of the malfunction. Perhaps he will clarify with you the details of the situation in which the breakdown occurred.

If the purpose of the diagnosis is to find out the cause of the malfunction, then it usually lasts about 20 minutes. Usually the details of the situation can significantly speed up the process.

4. Diagnostic results

After the technician has found out the cause of the breakdown, he will be able to tell what kind of repairs need to be carried out. You are given a list of necessary works and their cost, and after your consent, repairs begin.

You can wait for the repairs to be completed in our client area, you can take a walk along Tsvetnoy Boulevard (if, of course, you came to the central office), or you can go about your business and pick up the phone at another free time.

5. Repair

During repairs, our technicians work on your device, and you can wait with us or go about your business.

As soon as the repair is completed, the technician will hand over the ready device to the secretary, if you decide to wait with us. Otherwise, we will notify you of the completion of the repair by telephone.

6. Verification and payment

The repair is complete, all work is completed and you are ready to pick up your phone. You provide a document issued earlier, and we give you your device, which you can immediately check, and another document about the completion of the repair, cost and list of work.

You pick up the device and pay for repairs.

7*. Warranty case

If after repair the malfunction occurs again or another problem appears with your device, then you come or call us and bring the device.

If the case is under warranty, we perform repairs free of charge, under warranty. If not, then after diagnostics, we announce the cost (of course, you will probably be given a discount) for the repair, and then we carry it out.