Information that can be useful in self-diagnosis and troubleshooting

IPhone 5S Diagnostics

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

Phone diagnostics

In this article, we will not talk about the simple reasons for the breakdown - broken screens, old swollen batteries and stuck buttons, the purpose of this article is to shed some light on the diagnosis of the iP5S motherboard. All instructions provided below are designed for wizards and services who are just starting to understand component repair of motherboards. If you are not in the business of phone repair, then this article is not for you, you need. If you have 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. The SYSTEM-SERVICE company is not responsible for your actions after reading this article.

What you need to have before you start

1. Fine Sharp Probe Multimeter (well proven by Mastech)
2. A set of screwdrivers (pentalob, small cross, large cross for "double-deck" bolts that secure the board) (a set of screwdrivers for ali)
3. Several tweezers of different calibers (a set of tweezers for Ali)
4. Soldering station with a hair dryer (as well as flux and solder in the coil), the cheapest option is the YaXun 878D.
5. Laboratory power supply min. 0-5V 1A (any power supply unit within one thousand five hundred rubles in your supply store)
6. Understanding of basic circuitry (step-up, step-down converters, properties of basic elements of electronics, basic laws of electrical engineering)

So, before 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, try to remove it quickly and not overheat the microcircuits under it. Be sure to remove all black protective stickers from shields and around connectors (touch, display, battery, etc.) before heating with a hairdryer otherwise they will melt and when you need to remove them you will rip the 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 do not have the slightest idea what U7 is, then look at the circuit), under U7 (on the side opposite to the TOSHIBA memory chip) there are 8 capacitors, ring them, then go in a row 7 inductors, and under them a row of capacitors - power filters for the processor, SoC and GPU. All of these system components reside in a single A7 chip and are powered by U7. Orient the board so that the row of the aforementioned capacitors is closer to you, and the TOSHIBA memory chip is on the opposite side. Call capacitors with diode or regular dialing. 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 circuit, find the capacitors sitting on this rail. If the phone is after water, then, for sure, some containers are closed. Remove the most "suspicious" capacitors with a hair dryer 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 to determine the failed capacitor.

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

All capacitors were removed, but the short circuit remained

Drowned people may have a short circuit inside the BGA matrix under the chip. First, place the 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 corrodes and removes possible corrosion. Do not heat the chip to its melting point or wait for it to float. Heat to burn-off or vaporization temperature of the flux. After the board has cooled down, wash off the remaining flux, check the result. Did not help? Remove the chip if you have not done this before, good advice: do not spare the temperature, set the hair dryer to 400-450 and the minimum air flow, warm the target chip and "push" it with tweezers to feel the moment when it floats on the solder. Remove with tweezers or vacuum stripper. Then either reball (not recommended) or put a new one. In any case, clean the pads well with braid and change the flux several times. There should be no problems with the installation of the microcircuit, it will also "float".

There is no closure, but there is no start either.

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

Turned on, but not charging

On 5S, the TRISTAR chip is to blame for this. 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, the Q2 transistor (four-legged microcircuit) can create problems with charging, it can be replaced, in some cases a jumper is thrown there.

And if you need to check the entire smartphone? And if not iPhone, but Android? There is an option!

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

Why diagnose a 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 malfunctions and a booming aftermarket for smartphones required a fast and affordable diagnostic tool for the general public. This is what TestM became.

With TestM you can:

• check the functionality of the components of your smartphone and see what needs to be fixed;
• When buying an iPhone off-hand, ask the seller for a full TestM report to see the condition of the phone before buying;
• make a full report before selling your iPhone so that the buyer can see the condition of the phone.

Usually, for this work, the device is sent to a service center. He did this a hundred times, when he suddenly began to hear the interlocutor worse, the connection became unstable, the 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 malfunction. Although, believe me - this is not the worst thing that can happen. And TestM will help you save time, money and hassle.

How TestM replaces service center

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


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


The overall performance of the device and the performance of the system are assessed already at the first start. In addition to these, TestM offers a choice of 2 test suites: fast and complete. A quick check determines the quality of the work of the main components:

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

The complete set of smartphone test exercises in TestM does a lot more. You can check all types of sensors, network interfaces (including GPS), operation of hardware keys and vibration motor, camera components and charger operation.


I recommend doing exactly 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 the software responses of the hardware to the test request, the TestM set of checks verifies the actual operation of the 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, the touch of the touchscreen is recorded, the operation of the sensors is recorded, and the cameras form an image on the screen and are tested.


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


Then TestM analyzes the information received and compares it with the 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: are there excessive noise, are there 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 work is not an easy task, oh not an easy one.

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


The report is clear and simple: everything is in order with these components of the smartphone, others require careful study, and still others show poor-quality work.

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

What TestM is missing

I did a full smartphone test and analyzed the quality of the smartphone check using TestM. As expected, almost all tests make it possible to unmistakably state the health of the device's components.


You still have to apply a little ingenuity. TestM does not use flash and light sensor to test the camera, so it needs to be tested in good light. Flash and sensors are separate checks, separation is necessary for accuracy.


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

One more note: the "capacity" of the battery in TestM is estimated approximately. For an accurate check, several charge-discharge cycles are also required.

Instead of conclusions. The app that everyone needs

Shone Tell, co-founder of TestM, believes this utility will help simplify the sale and exchange of smartphones in the aftermarket:

“Hand-to-hand platforms such as eBay often allow sellers to hide the flaws of their smartphones and sell them for more than market value. TestM is an excellent verification and reporting tool for buyers and sellers. "

American-made "apple" gadgets have a fairly good reputation in terms of quality. But even the legendary iPhone, like any other thing, is not immune to possible breakdowns. The first sign that the smartphone is out of order is that it stopped turning on. But you should not immediately carry it to the service or, having sentenced to death, should not be thrown into the trash bin.

The reasons why the iPhone may not turn on can be roughly divided into two categories:

• system (everything related to the software component);
• mechanical (visible damage to the case and buttons or damage to parts inside the case).

Diagnosing iPhone system problems at home

As a rule, system malfunctions begin to manifest themselves at an earlier stage than the termination of switching on. At first, the smartphone may start to "slow down", glitch, applications will stop running, and so on. The reasons for unstable operation with the subsequent disconnection of the device may be hidden in the following:

• Unsuccessful self-opening of the system (Jailbreak).
• Operating system overload. If the smartphone is actively used with a connection to wireless networks, then the overload will not keep you waiting.
• iPhone has locked up after entering the wrong password.

All of the above system malfunctions can be corrected using recovery mode (DFU). Even a beginner can do this. It is only necessary:

• 1. Launch iTunes;
• 2. Connect the USB cable to your computer and smartphone;
• 3. Simultaneously hold down the home button ("Home") and the power button ("Power") and hold for 10 seconds;
• 4. Release the "Power" button, and hold "Home" for another 10 seconds;

After these steps, iTunes should detect the iPhone in DFU (recovery) mode and activate it. Once the process is complete, the gadget can be turned on and checked that the problem is gone and it works like new. If the recovery mode did not help, but outwardly the smartphone is intact, then it makes sense to repeat the above steps again. In other cases, the iPhone should be returned to a service center.

Diagnosing iPhone mechanical problems at home

With mechanical damage, everything is much more difficult. The reasons for the breakdown of a smartphone are usually the same: the iPhone fell, “bathed” in water, hit, and so on. As a result of these adventures, the gadget stops turning on, cracks, chips and scratches appear on the case and display. Also, the processor of the device itself may fail, which is even worse, since the repair will cost much more (a complete replacement of the entire board will be required). Well, the most innocuous thing that can happen to an iPhone is that the battery's life will come to an end. The problem, accordingly, is solved by simply replacing the battery.

How to fix an iPhone at home

If you buy component parts and tools, then you can try to fix the device yourself. To do this, remove the back cover with a special screwdriver. As a rule, it is she who creates the greatest difficulties. And replace damaged parts (buttons, glass or sensor). When bringing the iPhone back to life, it is important that the workplace is kept as clean as possible, as dust can negate all efforts. If you are not sure that your skills will be enough to repair the gadget, then it is better to entrust it to the hands of professionals.

Used to diagnose hardware problems on Macs manufactured before June 2013. But if your device is younger, ANT will no longer start on it: instead, the computer will use the Apple Diagnostics program.

In fact, both programs are not much different from each other. Unless Hardware Test has a simpler and older interface, while Apple Diagnostics has everything done in a new “flat” stylish design. In addition, the latter is adapted to the latest Apple computers and diagnoses and diagnoses problems with the internal hardware components of the computer, such as the motherboard, memory and wireless devices.

If you think your Mac is having hardware problems, there is a handy way to check it out.

To get started, turn off your computer and turn it on while holding down the D key until the Apple Diagnostics boot screen appears.

After that, select a language - this will make it easier to work with the program.

The basic test takes two to three minutes. If no problems are found, you will see a corresponding message. But if there are problems, the system will not only find them, but also describe in detail what could be the matter, and for some problems it will offer solutions before contacting the service center.

Under each error, you will find its unique code - if the problem is serious, it is better not to self-medicate. For warranty computers, you need to contact, tell her the error code, after which the specialists will tell you what to do next. Do not despair if your Mac is no longer under warranty - as a rule, they know all the error codes and will be able to immediately tell you how much the repair might cost.

To exit Apple Diagnostics, shut down your computer. If you want to immediately contact the company's support, click "Get started".