Professional cellphone repair guide and high quality cellphone repair tools

We received an iPhone 6S and the fault description was that the iPhone 6S showed a large current when it was turned on. Why does this happen? How to repair it? When test the iPhone 6S with DC power supply , the current value is shown as picture. 1. According to our past phone repair experience, there is no obvious corrosion or serious pressure on the motherboard, so we first test the motherboard PP3V0, USB and NAND power supply. 2. In the maintenance process, if you encounter the same situation:  the motherboard is large current and also can be turned on, if the motherboard and above several circuit PP3V0 are all normal, you can first install the iPhone to test function, if all the function is normal, then your lips can be touched to test whether the temperature of USB is heating, the iPhone 6S motherboard we test through the lips, it is found the USB is extreme heating, so it is determined that the USB causes large current. 3. As shown in picture, the current...

We received an iPhone 6 and the fault was that the iPhone didn't touch at all, and the iPhone 6's touch function didn't work. The iPhone white touch IC that doesn't work is completely untouched. How to fix it? The following is a detailed repair step. After removing the iPhone motherboard, we found that the iPhone black and white touch IC has been replaced by the original repair personnel. Measure the working state of the iPhone black and white touch IC and measure the 5.1V and 1.8V of the iPhone white touch IC . The iPhone black touch IC +5.7V -5.7V and 1.8V power supply. After measure them with digital multimeter , all the data tested is normal. Remove the iPhone black and white touch IC, and then measure the diode data for the solder pad, it is normal. Based on previous repair experience, we know that the iPhone 6 Plus display socket synchronous signal inductance easy to empty weld and causes iPhone no touch at all. The data of iPhone 6 display soc...

We received an iPhone 7, the customer said that he refreshed the iPhone 7, then the phone became iTunes mode and reported error 4013. Have you ever encountered this situation? How to fix it? In this mobile phone repair tutorial, you will find a way to solve it. According to our experience, we know that mobile phones have signal problems. Generally, we should first detect the baseband. If there is a problem with the base, don't try to refresh it again, because there will be an error (error 4013, the progress bar will go to 60% or 80% position will report - 1). It is found that there is a problem in the baseband. Since the iPhone is iTunes data cable mode, the voltage can not be measured. So we can only use Fluke digital multimer to check whether the resistance of each circuit of baseband power supply is normal. The test points of each circuit can be found more accurately based on the WUXINJI schematic diagram , and the corresponding components can be found on the bitmap f...

Have you ever encountered an iPhone 6 that cannot be turned on?  If the phone can't start, I believe we will be very anxious at this time. Yesterday, a friend sent us an iPhone 6 need to be repaired, the iPhone 6 directly short-circuit after connected it to DC power supply, large current short circuit and iPhone motherboard is overheating. We think it's small problem, disassemble the iPhone, and we found the iPhone charge tube is hot. Remove the shield cover and apply some rosin, obviously the iPhone baseband power is damaged. Remove the iPhone baseband power and then connect iPhone logic to DC power supply, the iPhone boot, but no display, check it more clearly, several pins on the socket are damaged. As shown in picture. Remove the socket, clean up the solder pad, and then re-solder the good socket to it. After replacement, the iPhone can be turned on normally, but there is no baseband. Install the new iPhone baseband power, but there's no SIM card malfunction,...

I believe that most users have encountered a sudden black screen when using the iPhone6. Our customers are the same. The iPhone 6 can be turned on, but the screen is black and not lit. His iPhone 6 can talk normally and can also be connected to the Ace Assistant. According to his description, mobile phones can be turned on, connect to computers and make phone calls.Based on our experience, there may be problems on the iPhone 6 display or backlight. Disassemble the phone and connect adjustable DC power supply , it is found electricity leakage, there is no back light after turning on, but with the light we can see the apple Logo. Remove the iPhone main board, we found there are water corrosion marks. Observe under a Trinocular Stereo Microscope , as shown in picture. Pry out the corroded components, remove the backlight chip, two stage tube, backlight boost inductor, and connect the adjustable power supply, it is without leakage this time. welding back the backlight ch...

Our customer sent us an iPhone 7 and the baseband has a problems.How to repair it? We believe many phone repair personnel have repaired the problem of Phone 6 Plus touch M1, iPhone 6 baseband u1v1 and iPhone 7 audio problems. At first, we used the method of welding iPhone touch IC or re-install touch IC to fix iPhone 6P touch problem, but after a while it need to be repaired again. Later, we all know that we can fix this problem completely by soldering the jump wire . The baseband u1v1 and audio problems can also be used in the same way. The first layer of these iPhone motherboard layer circuit lines is very fragile, easy to disconnect or virtual welding, some are not broken by the naked eye, but in fact it is almost disconnected, weak links, at a critical point. Now, let's back to iPhone 7 baseband problem, most people think it is Qualcomm baseband problem, and we think it's still the same as before, it's iPhone motherboard design flaws. Check the working schema...

The customer sent an iPhone 6S Plus. When the iPhone 6S Plus in normal use, the screen of the mobile phone is half black. After analysis, we know that such a fault is generally a backlight circuit problem.How to repair it? Here is the repair tutorial. Because the last repairman described the iPhone motherboard has connected tin, so there was no direct test on DC power supply . Disassemble the iPhone 6s Plus and observe the main board under LED Stereo Microscope , we find there is connected tin in the fingerprint base. After cleaning up the board, we connected the power supply for testing and found that the fault was a half-black screen, which is consistent with the customer description. When use Fluke digital multimeter to measure the ground value of the iPhone touch base , it shows that the 6 pin of the display base are infinitely large, indicating that the pin is broken. 6 pin is backlight power supply, which is through the FL4211 inductor to the backlight chip, sinc...

We received an iPhone 7 Plus and the fault description was no service. After insert the SIM card, the iPhone 7 Plus always in searching, and it has no IMEI when dialing the *#06#. Check Settings on iPhone, there are IM and Modem Firmware numbers. After reset the iPhone network settings,  the problem still there. How to repair it ? For this fault，please don't flash the iPhone first, if the iPhone baseband CPU has some problem, then it will report unknown error 4013 on iPhone 6S and above, for 7 and 7P, we need to notice iPhone baseband 1.0V power supply circuit. If iPhone baseband power supply is short circuit, then basically it's caused by damaged iPhone CPU, so we need to measure the resistance for this circuit before we start to repair. For an iPhone with an iTunes 4013 error, we can heat iPhone baseband power, and then flash it. Open the WUXINJI Dongle , and then compare with the iPhone schematic diagram and iPhone motherboard bitmap to measure the iPhone circuit...

We received an iPhone X  from our customer. He described the fault is not to boot after the phone drop accidentally. It reports error 56 when restore the iPhone X. How to repair this fault? Please read the following article. Because the iPhone X is a two-board connected through the middle column, it is easy to drop the line. It might have detached from the NFC chip pads to the CPU block. Disassemble the iPhone X by iPhone opening tools , take the upper board off the main board, when separate the main board we see a row of points have fell off. Look at the location map on WUXINJI dongle , it is surrounded by a ground wire, in fact, there are 6 useful points dropped. The ground wire does not need to be filled, the 6 useful points are added by professional phone welding tools. These are the signal wires of the NFC chip, so the iPhone X would report error 56. Then the tin of the middle column is repaired by iPhone X BGA reballing stencil , and the AP part is welded ba...

What should we do if our iPhone 6 no display ? How to repair it ? The iPhone 6 doesn't display after boot, first connect it to DPS DC power supply to check the current, the iPhone boot current tested is normal, the iPhone 6 turned on but the screen no display.  Disassemble the iPhone logic board and observe it under the Stereo Zoom Microscope , We found that the iPhone Nand flash had been fixed before, and the other parts did not. However, since the iPhone Nand flash is not related to display, we can ignore this problem. Using a digital multimeter to measure the resistance of the display socket, we found that all resistance values are normal. Since the resistance is normal, then we need to measure the display power.  Install the iPhone display screen and test it, the display +5.7V and -5.7V all are normal, but when measuring the 1.8V voltage of the display reset, no voltage was found. After checking the iPhone schematic on WUXINJI Dongle , we know that the di...

Recently, some users have reported on the Internet that the iPhone6P front camera cannot be used normally. and the distance sensor has problem too. How to repair it? Please see the article below. The two failures are concentrated on the front camera flex cable, which is likely to be caused by the damage of the wiring. First, we have to eliminate the possibility of the external parts fault, then consider the motherboard problem. After removing the screen components and replacing the screen components, we still can't open the front camera and use the distance sensor. Disassemble to measure the ground resistance of the front camera seat of J1111 by Fluke digital multimeter , it is found that several pins are infinitely large, and the related inductors are loose when touch with the pen. It seems that the small components are pseudo welded. As shown in picture. Remove the motherboard and observe it under the Trinocular Stereo Microscope , we can see that the touch was r...

Have you ever encountered a situation where the compass cannot be used? This is very inconvenient for us, and our customers have encountered this situation. He sent us an iPhone 7 Plus. The problem is that the iPhone 7 Plus compass is not working properly. This is not normal. We need to repair it. After we received the iPhone 7 Plus, get into IOS to test the iPhone compass function, it doesn't work. Disassemble the iPhone 7 Plus by phone opening tools , take out the iPhone motherboard. The appearance of iPhone motherboard looks good, but there are traces of moldy around the gyroscope. Carefully clean up the moldy areas, and then connect it to DC power supply , it boots normally. Install the iPhone, and test it, everything is fine, except the compass. For this case, some people will think it's the compass problem, and it can be fixed by replacing the new compass; some people will think that the gyroscope is virtual welded, because the gyroscope is moldy, it can be fixe...

Many users report that the iPhone7 screen is blurry, and we have encountered the same situation. Our customer sent us an iPhone 7 with a blurred screen. In view of this situation,how to repair it? Let's learn how to repair it. After receiving the cell phone, what we need to do first is to test it and confirm the fault. Disassemble the phone with iPhone 7 opening tools carefully and observe the main board. We found this motherboard is a pretty board, according to the previous maintenance experience, the iPhone display base needs to have a test with Fluke digital multimeter . It is found that the resistance of the 17th pin showing the J4502 resistance of the base is infinite, and the normal resistance should be more than 400. This pin is powered by the screen 1.8V. This point is connected with the inductance DL3906 through reading on WUXINJI schematic diagram. The other end of the inductance is measured normally, so we replace a new inductance FL3906. Rei...

When using a mobile phone, I believe that everyone has encountered the phenomenon of water in the mobile phone. Our customers are the same. According to his description, the iPhone 6S accidentally dropped into the water and no display after booting. How to fix it? What tools do we need? Please read this article to find the answer. We press the iPhone power button, after for a while, the screen still is black, we try to use another iPhone to call it, the iPhone 6S has response, but the iPhone screen still doesn't display. We need to repair it. First of all, disassemble the iPhone by phone opening tools, and carefully remove the iPhone logic board. Connect iPhone to the DC power supply to measure its boot current, the current tested is normal, no large current failure, now we need to check if it has a display but no backlights. Check it under the light, we find the iPhone has a display. Measure the display socket by Fluke 15B+ Digital Multimeter , we find some pins are ...

We received an iPhone 6P from the customer, the fault description was that when the iPhone motherboard and DC power supply  were connected, the current was normal. After the screen was installed and tested, there was no light or display. According to the customer's description, it is inferred that it is sometimes displayed and sometimes not displayed. How to repair it? In this article, you will get the answer. By observing the appearance of the motherboard, we can not directly determine the fault point, the measurement of the display base resistance to the ground and power supply are normal, after the replacement of display IC U1501, the iPhone 6P is still not displayed. In view of the fact that the 6P motherboard is easy to get broken by pressure or false welded , we have to remove the U1501 and use Fluke digital multimeter to measure the pin resistance. Fortunately, when the B2 pin is measured no resistance, we know the fault is finally found. The B2 pin was supplied b...

The iPhone 7 Plus is equipped with a dual camera design that greatly enhances the user's shooting experience. Perhaps it is the reason for the new design. Recently, some users have reported that the camera on this model has a problem when it is used, the problem is that the iPhone 7 Plus front camera not working. How to repair it? First, we  need to test it. Turn on the iPhone 7 Plus, get into IOS, open the iPhone camera icon, and iPhone rear camera is normal, switch it to iPhone front camera , the iPhone 7 Plus front camera not working, it displays black. Disassemble the iPhone 7 Plus by phone opening tools, carefully remove the iPhone motherboard. Put iPhone motherboard on the WL Aluminum Alloy Pad . Measure the ground resistance for iPhone front camera socket J4503 by Fluke 15B+ Digital Multimeter , the data tested is normal. And then measure the iPhone front camera power supply, the data tested also is normal. However, when we measure the I2C bus, we find the volta...