博文

目前显示的是 八月, 2018的博文

Repair guide: iPhone 6S won't wake up after standby

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We received an iPhone 6S, the customer described the iPhone vibration and ringtones working properly. This means that the iPhone is turned on and does not display the iPhone LCD screen. The customer said that the iPhone was fixed in other places before, and after a few days of use, it was destroyed again, which is the same failure. How should we fix it? We start to disassemble the iPhone, finding that the screws on the bottom are missing, after disassembling, the screws inside are also missing a lot. This is common failure on iPhone 6S, the repair idea is that the system signal interruption or the power supply and clock are unstable, and most commonly is iPhone display circuit problem. Although there are many screws missing after disassemble the iPhone, but we don't found any repair trace of repairing. Considering this iPhone has a low chance of failure,so we start to repair from the simplest way, try to replace the iPhone display assembly . After replacement, test the iPhone

What should I do if the iPhone 7 Plus camera fails?

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If our iPhone camera doesn't work. That feeling is definitely very bad.Our customers are in this situation. He sent an iPhone 7 Plus to us, the fault described is that the iPhone no camera, after replace the new iPhone rear camera, the fault still there.  This iPhone was repaired before, the previous phone repair shop repaired the iPhone WIFI module IC and U3301 iPhone audio IC . According to previous repair experience, we know there are 2 camera power supply transfer tube on the WIFI IC are easy to virtual weld, after remove it, and reinstall it, the failure still there. Use the digital multimeter to measure the grounding resistance of the iPhone rear camera J3001 and J4501, and the data is normal. It is also normal to test the power of the camera socket. Measure the I2C bus on J3001 and J450. When measuring the J3001 2 pin, it is found to be only 0.4V, but under normal conditions, the normal voltage of the I2C bus should be around 1.8V. Open the WUXINJI Dongle to

Why Does My iPhone 6 LCD Display Failure?

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We received an iPhone 6. The customer said that the other functions of the iPhone are normal, but the iPhone LCD is sometimes displayed, but sometimes it is not displayed. This looks very troublesome, how do we repair this phone? Open the iPhone 6 for testing and the iPhone LCD screen is not displayed. Removing the iPhone motherboard and observing it under the stereo zoom microscope , we found that there is a lot of solder paste on the iPhone monitor socket and the iPhone touch socket. Is the iPhone LCD screen not display because the socket is not clean? First we use BGA clean water to clean the iPhone motherboard. Because the customer said that iPhone LCD screen also is half bright and half the screen black state, so, after cleaning, we can use digital multimeter to measure the grounding resistance value for the J2019 display socket 1 pin PP_LCM_BL_CAT2_CONN and 4 pin PP_LCM_BL_CAT1_CONN, these two pins will cause iPhone screen half bright and half black problem. We foun

How to fix iPhone 6P can't charge and display error 1

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iPhone 6 Plus has the same problem that it can't be charged like other mobile phones. We received an iPhone 6 Plus. When the iPhone 6 Plus is charging, there is a phenomenon that the charging does not respond and cannot be charged, and an error 1 is reported when it is refreshed. The customer said that he did not know how to solve this problem? He needs us to repair it. Based on our past experience, the iPhone 6 Plus error-1 error is usually caused by a baseband circuit or a baseband chip. After removing the shield, traces of well water corrosion were found in the iPhone Charging IC and baseband power. After cleaning the motherboard, replace the baseband power supply and charge IC. Reflash the iPhone, it can not be charged after entering the system, after plugging in the data cable, it prompts does not support this accessories. According to past repair experience, this fault is caused by the lack of power supply condition of USB chip. While testing USB operating c

How can we repair iPhone 7 can't turn on after water damaged

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The user sent us an iPhone 7, and his iPhone 7 could not be activated after falling into the water. There is no response to charging. For water-damaged iPhones, first we need to check the appearance of the iPhone. In general, parts that are already in the water are easily damaged. After detecting the appearance, we need to connect the DC power supply to check the iPhone status. Connect iPhone motherboard to DC Power supply, no leakage, press the iPhone power button, the current jumps from 200mA, this failure mostly is caused by power supply short circuit, it also can be measured, just check the several power supply circuits that is output by the main power supply. After measuring these power supply circuits, we can identify where the short circuit part is. When measured the PP3V0_TRISTAR_ANT_PROX this signal, we found it is short circuit. This signal is reached to these place and USB, we can check it on iPhone 7 schematic diagram . Directly remove the USB, and

How To Repair iPhone SE Short Circuit and Reboot Failure?

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The customer sent us an iPhone SE. The fault described is a short circuit in the phone and cannot be restarted. How can we fix it for this situation? What repair tools do we need? Please follow the steps below. First, remove the motherboard and feel the hot position with your hands. However, the location of the heating part is not obvious. Apply some rosin on the motherboard and connect DC power supply again, we still can't find the fault part. The circuit is converted from battery to main power supply through the conversion tube Q2300. Remove the Q2300 and measure the grounding resistance with the Fluke multimeter to see if there is a short circuit in the battery or the main supply. It is found that there is a short circuit in the main power supply connecting component by value evaluation. Rosin some rosin on the main power supply connecting component again. The C2331 melts instantly when the single circuit is energized. It seems that the fault point is her

Repair iPhone 6S Plus can not charge and leakage 100mA failure

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One customer sent us an iPhone 6S Plus, and the fault description was nothing when the charger was plugged in.The customer said that his iPhone did not drop or enter the water. why does this happen? We disassemble the iPhone and test it, it's leaking 100mA, turn on iPhone, the iPhone can be entered the IOS normally. Replace the external configuration and charge it, still no response. The voltage of iPhone battery socket tested only has 0.6V, according to our repair experience, it is caused by U2. Remove the iPhone U2 IC , but the iPhone is still leaking 100mA, the resistance value of the bottom pin measured is normal. Replace the new iPhone U2 IC, assemble the iPhone to test, it charges normally, after a while, even if we don't use the iPhone, but the iPhone battery still consumes fast, we need to find out where the leak is. Take off the iPhone motherboard again, connect it to DC power supply and test it, after heating a while, we can feel the overheat place,the iPh

Error 56 On IPhone 7 Plus,what should we do?

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We received an iPhone 7P that displays the iTunes icon. When connected to a computer for recovery, it reports an 80% error 56 with the same error code as the previous model, usually caused by camera power and NFC. How can we repair it? There is no abnormality in the resistance value of the power supply of each circuit of the camera. Check the NFC section, there is a common fault in the iPhone 7P. The NFC power supply tube in the upper left corner of the CPU can be connected short first. As shown in picture. Short connect the A1 and A2 pin on the NFC power supply pipe, then restore to test after short connection. This iPhone 7P is still not able to pass after that, so we can only take NFC to test. As shown in picture. It is no problem to test the resistance of the socket by Fluke digital multimeter , reball the NFC module with iPhone BGA reballing stencil , install the NFC module and restore the phone after installation, but the mobile phone does not carry out the second

Repair Guide:iPhone X cannot be charged after it falls

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The iPhone X is powerful and features a full screen. Has been favored by the majority of consumers. However, even the best mobile phones will fail. We received an iPhone X, the fault described is that the charging icon is displayed normally, but the iPhone X cannot be charged after it falls. Turn on the iPhone X to detect it and the fault is real. After communicating with the customer, the customer agreed to repair the iPhone X. After testing, the iPhone X charge icon can display normally,but iPhone power percentage is getting less when it in charging, this is actually a not charge failure. According to our repair experience, for the dropped damaged iPhone, the L3340 and L3341 inductors of the iPhone charge IC are easy to empty weld and pin missing. Connect iPhone charging cable to the iPhone X tail plug flex cable, and then test the cathode of iPhone battery by UNI-T UT658 USB Tester , no voltage was found, so we judge the fault is in the charging part. If you want to del

WiFi does not work on iPhone 6 , how to repair it?

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We received an iPhone 6, the customer described that no matter how to try, WIFI can not be opened. The customer said that he is more anxious to use the phone, so we need to fix it quickly. After deleting WIFI, the activation screen appears. Connection test We found that the iPhone 6 WIFI chip  was not installed, the data cable was not installed in the startup activation mode, and when we connected the Aisi assistant, we found the serial number without the baseband. It enters into the activation mode again after using for a while , which is usually baseband power output short circuit based on our usual maintenance experience. Considering the WIFI removal situation, associated with the WIFI edge of the GPS power amplifier has a voltage output baseband power. Measure with a FLUKE digital multimeter , it's PP_LDO13 as shown in picture. As shown in picture. After eliminating the short circuit, the result is that the C5129 is broken, the resistance is back to normal, connec

How to repair iPhone 6 Plus touch failure after dropped

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The customer sent us an iPhone 6 Plus, which once dropped the iPhone 6 Plus to the ground, and the iPhone 6P did not respond to the touch. The touch screen did not respond. As we all know, M1 pin easy disconnect is a common failure for the iPhone 6 Plus, whatever iPhone is a drop or used a long time, this should be a design flaw in the motherboard. M1 pin is the sync signal from iPhone display screen to touch communication, the symptom of this failure is that sometimes the touch is completely not working, and there are white lines appear above the iPhone display screen. Start to measure. After turn on iPhone, and touch function and display function tested are normal. In this case, there is a way that touches this position of the front socket by your fingers (because the back is the iPhone black touch IC , if there are some problem on M1 pin, then the failure will be shown clearly. After the test, the failure has been shown, start to repair. Disassemble the iPhone, th

How to repair iPhone 6P WiFi does not work

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We received an iPhone 6P with WiFi failure. According to the customer's description, the iPhone 6P device has been fixed before, but it has not been well fixed. First, we need to detect the phone to make sure WiFi is not available and other features are working. Disassemble the iPhone and detect the iPhone 6P motherboard carefully, it is found that the WiFi module was not installed, also there are a lot of solder points fallen off. As shown in picture 1. Check the WUXINJ I bitmap and find out the 32K clock signal pin of WiFi is lost. Bluetooth synchronization control, clock and so on, Bluetooth foot position directly through the iPhone CPU Then dig the pin to fly jumper wire and apply some green oil. Welding the original WIFI and turn on the iPhone to test, it's gray WIFI too, and the device also stuck. After we replace a new one, the fault is still same. Didn't the WIFI install well, we heat it directly and put the tweezers on the WiFi module. Reinstall t