Professional Cell Phone Repair Guide

Have you ever met the same accident on your iPhone 6? It's not turning on after dropped into water accidentally. It seems also a very common phenomenon. How to repair it? Of course, we need to diagnose the problem first before detailed repair on the water damaged iPhone 6 device. Let's read the article guide! 1. Tear down the iPhone 6 by cell phone opening tools, connect iPhone motherboard to DC power supply , and then press iPhone power button, the current stuck on 750MA. 2. Use  UNI-T UT81C Scope Digital Multimeter   to measure each circuit output for iPhone power IC, there is no  any short circuits. 3. According to our experience, actually, for this problem, the best way is rosin method. 4. Apply some rosin on the iPhone 6 motherboard, and then use PPD 861D Plus  hotair rework station to smoke the iPhone motherboard until it turns white. Supply power and boot it, after a while, do the same thing for several times. Then you will find t...

It's really annoying that you are unable to use your camera in a normal way? You also meet the same status? iPhone 7 camera cannot be opened? it's ok for taking videos but it fails to take pictures? or it's ok for taking pictures but unable to save in cell phone? If you have encountered one of these failures, please follow the steps to have your repair operation! Use a Fluke 15B+ High Performance Digital Multimeter   to test the power supply status as following ( When the iPhone 7 camera function is on and the screen lights up) : After turning on the iPhone 7 device, the PP1V8_UT (1.8V), PP3V0_UT_SVDD (3.0V) can be measured, however, the PP2V8_UT_AF (2.8V, PP2V9_UT_AVDD aggregation voltage) (2.9V), PP1V2_UT_VDD (1.2V) these three circuits of power supply only can be measured when the iPhone7 camera   under good state, the PP2V9_UT_AVDD circuit power supply is provided by the U2501, the U2501 is very easy to cause camera working abnormally. The best solution i...

The audio parts of iPhone are mainly including audio decode, u0900, ringtone (horn), and amplifier. Check the iPhone 6 diagram on  wuxinji dongle . We can see that the iPhone audio integrated circuit has 4 circuits, one is vcc_main, 3.7V, the other three is 1.8V. After checking the power part , then we check the iPhone audio channel part, we can see the direction of the audio signal on iPhone schematic diagram. At first, check the normal call mode.  Two microphone signals LOWERMIC1_TO_CODEC_N_CONN, LOWERMIC1_TO_CODEC_P_CONN through iPhone tail plug flex cable  and 17/18 pin of tail plug interface J1817, after the inductance FL1881, FL1882, finally through the capacitor C0922, C0923 send to audio IC-- U0900.  The 1.8V power supply signal PP_CODEC_TO_MIC1_BIAS that was sent from audio IC U0900, through FL1 and 21 Pin of interface J1817, after through tail plug circuit, the final supply to the microphone. This is the process of microphone signal. The iPhone ...

Your iPhone 6 is not able to power on? And it also shows power leakage when connecting with DC power supply? How to fix the problem? In this article, you will get to know the detailed iPhone 6 boot failure repair process, hope it will be helpful for your iPhone repair work! Electricity leakage can divide into two kinds: 1. when iPhone 6 not booting, it will shows leakage or large current alarm on UD 1505TA DC power supply . 2. There is no electricity leakage when supplying power, but it will show large current once pressing power button. The iPhone 6 battery voltage is PP_BATT_VCC first sent to charging IC--U1401, then U1401 will output main power PP_VCC_MAIN to the  related circuit, battery voltage PP_BATT_VCC and main power supply PP_VCC_MAIN is sent to the related board after supplying power, if it shows power leakage or large current not booting, it must be one of the PP_BATT_VCC and PP_VCC_MAIN circuit has a short fault, first measuring the ground resistance of PP_BATT_V...

If the fingerprint and home button function on iPhone 7 / 7p get failure and you don't know how to fix it, now this article will be your guide for the detailed repair process! Hope it will help!   Before repairing, open the WUXINJIDongle  to check iPhone 7/7P schematic diagram. 1. iPhone 7/7P home button repair guide The home button power supply schematic diagram is as follows: The power supply pipe U3801 output PP2V75_MAMBA(275V) to J3801, iPhone power IC  output PP1V8_TOUCH(1.8V) , through resistance R3805, final to J38011. If these two circuit power supply is abnormal, it will cause iPhone home button  failure . For repairing this problem, check short connection R3805, and then you can replace the U3801 or disassemble the U3801, and then use PPD 861D Plus   hot air rework station to weld the jump wire from C3813 to C3823. Tips: PP3V0_MESA(3.0V), PP1V8_MESA(1.8V), PP2V75_MAMBA(2.75V) and PP1V8_TOUCH(1.8V), this four circuits ...

Are you fail to use fingerprint function on your iPhone 6? It's really frustrating that you can't enter into the home page of your own phone. Generally there are lots of reasons may result in the problem. In this article, we will list several possible damaged parts for your reference, hope it will help! Inductor 1500 easily corroded damage caused by water damage, which will cause U1503 can not work normally, it's necessary to replace if the inductor gets damaged. Since the small glass U1503 IC voltage value is 3.7V  (VCC_MAIN) when iPhone is not booting and it has high voltage output value 16.5V when working, so if the IC gets water in, it would very easy to be damaged or short, which not only cause the fingerprint recognition failure but also cause leakage or high current when connecting with Rigol DP832 DP832A DC power supply . The HOME button signal passes through the 3 tracks of the interface J2118 and then passes R2160 to iPhone 6 CPU . Here we should notice that...

The most obvious design changes are iPhone 8 and 8 Plus back glass, and the price to replace the glass is very expensive. In your daily life, basically you can't break the glass of your mobile phone, and you may throw out a lot of cash. We comb the features of iPhone 8's screen and glass rear cover, including: on the back of iPhone 8, our spy iPhone's fashionable new glass lining has seven layers of color to finish. When apple is guaranteed to every user, the rear panel is reinforced with "internal laser welded steel and copper structure", but we also find that time and durability test will tell you whether the phone will be broken or cracked. Repair Steps: 1. After removing the pentalobe screws, we need some heat as an antidote to the waterproof display seals 2. Apply the Doule Suction Cup Pliers after the Seals softened, it is in order to get some pulling power, and slice through the adhesive with a little help from cleaning tool, such as the BGA Paver S...

Since the size of iPhone6s plus screen display  is large, it's necessary to use two sets of background lights to supply power, one is provided by U4020, the other is provided by U4050. 2  sets of circuit 1) PP_LCM_BL_ANODE,     PP_LCM_CAT1, PP_LCM_BL_CAT2 2) PP_LCM_BL34_ANODE,  PP_LCM_BL_CAT3, PP_LCM_BL_CAT4 For PP_LCM_BL_ANODE and PP_LCM_BL34_ANODE, if one of the circuit has no voltage value, it will cause the iPhone 6s Plus screen to be half bright and half dark. For PP_LCM_CAT1, PP_LCM_BL_CAT2, PP_LCM_BL_CAT3 and PP_LCM_BL_CAT4, if one of  these four circuits gets abnormal signal, it will cause the 1/4 screen to be dark. Solution: Use jumper wire  to short connect PP_LCM_CAT1 and PP_LCM_BL_CAT2 or you can also connect PP_LCM_CAT3 and PP_LCM_BL_CAT4. The control signals of these two sets of backlights, one group of inductors FL4211 FL4212 FL4213 are sent to the display interface. The other group is sent to the display interface...

Today, mobile phones have popularized our life, no matter how careful we are, some accidents can never be avoided. When the cell phone is broken, many people will face the same question: do I fix it or replace it? Especially when you buy a new and expensive phone like iPhone 8, the situation of iPhone damage can be divided into many kinds. It may be the damage of LCD, ICs and any other parts, which will affect the appearance and internal operation of mobile phones. However, not all problems need a lot of energy and money to repair by technician or iPhone repair tools . Sometimes there are some simple solutions to repair common cell phone failures. If they can solve the problem on your mobile phone, you can save a lot of money. Repairing mobile phones is usually cheaper than you think, because people think that because smart phones are so expensive, they may at least spend the phone itself to solve all kinds of problems. In general, however, this is the opposite of what you assume....

We are going to fix an faulty iPhone 6 today, customer reflects the fingerprint of his iPhone 6 fingerprint got unresponsive, after recovery, the phone reports error 53 and unable to reboot again. Disassemble the iPhone 6 device and use DC power supply  to test, when power on the iPhone 6  (click the power button moment), the current value reaches 200-250MA. The current value of normal iPhone should be around 50-60 Ma. It is obvious that there is a leakage of electricity. Leakage and fingerprint failure, it can be preliminarly judged that the fingerprint part has electric leakage phenomenon, resulting in fingerprint failure. And for the error 53. First, measure the 2 power supply of fingerprint. 3.0V voltage is measured low. The value is very close to short circuit! So it can be judged the problem is 3.0V short-circuit, which caused by low power 3.0V on fingerprint so that it would get unresponsive, for error 53, now we know the circuit is short, of course the rosi...

We are going to fix iPhone 6S fingerprint failure. Check circuit diagram of iPhone 6S fingerprint line interface on WUXINJI Dongle , the difference with iPhone 6 is that the iPhone 6S has more circuit. The left of the fingerprint line interface circuit map is control signal of fingerprint; the right part is new function--Force Touch, also called pressure feeling control.   We get to know from schematic diagram that the power supply of fingerprint has 3 circuits, one is 1.8V, one is 3.0V and another one is 16.5V. If the 1.8V and 3.0V is abnormal, it cause fingerprint failed to turn on, these two voltages can be reached to fingerprint interface when you press the iPhone power button. The   3.0V and 1.8V  voltage is supplied from iPhone power IC . If the circuit of 16.5V is abnormal, it will cause the iPhone can open the button that adds fingerprints, but there is no response when you add fingerprint. This voltage will be measured 16.5V when the fingerpri...

Have you ever met iPhone 5s booting failure? There are several situations for iPhone 5S booting failure. Before repairing, you need to observe and test the damaged part first. 1. large current value Use DC power supply  to have a test, If iPhone 5S has large power current and fails to boot, it is often caused by one of the circuit from PP_BATT_VCC or PP_VCC_MAIN is short-circuit, the solution is same as the power leakage repair. 2.No power leakage when power off, large current when press power button This situation is a short-circuit of the output of the power IC. Measure the ground resistance of each output of the power IC with Fluke 15B+ Digital Multimeter  , and find out where the short-circuit part is. Then replace it. 3. Booting with 50 Ma Current Most of this fault is caused by the iPhone 5S CPU  or NAND is damaged, repair will be very difficult! Because the iPhone NAND is not a single change, and the cost of CPU is also expensive, the success possibil...

Charging failure is a common problem in cell phone repairs, here we are going to talk about how to test and repair iPhone 6S Plus charging failure. iPhone 6S Plus charging failure, including the iPhone battery  power percentage is getting less during the charging, power down status can be charged successfully but cannot charge after boot and unable to recognize USB, etc. Check iPhone schematic diagram on WUXINJI Dongle , we found that the PP5V0_USB(5.0V) that was sent from the iPhone Tail Plug circuit, and then continue sent to the charging IC via the trailing plug interface, and then go through the charging protect tube, finally send it to iPhone USB control IC. After disassemble the iPhone by phone opening tools, remove the iPhone motherboard, use Fluke 15B+Digital Multimeter   to measure the 5.0V voltage (PP5V0_USB) next to the charging IC, and then measure the 5.0V voltage (PP5V0_USB) next to the USB control IC to check is it working properly. If both th...

How should iPhone 7 7P be repaired if there is boot failure and power leakage? The battery voltage VBATT is firstly sent to the iPhone 7 charging IC , it outputs the main power PP_VCC_MAIN and then supply to the power supply IC and other related circuits. When the power button is pressed, the IC output voltage of the power supply is supplied to iPhone 7 CPU , NAND and other related circuits respectively. The battery voltage VBATT and the main power supply VCC_MAIN are sent to the relevant circuit before turning on the iPhone 7, in this case, if there is power leakage or large current when connecting with DC power supply , it means that either the battery voltage VBATT or main power fupply PP_VCC_MAIN has short power leakage component. There are plenty of components are connected with these 2 circuit, use rosin will help you to find the damaged one quickly. Specific methods are as follows: 1. Measuring the of the grounding resistance of the iPhone 7 battery voltage and the mai...

In this article, you will get to know how to choose the most suitable cell phone PCB repair holder, if you are a professional cell phone repair technician, you must know that a PCB repair holder is essential in daily repairs, so it's very important to choose a better one, how to choose? Please read the following points: 1. Choose a cell phone PCB holder that easily adjusted to accommodate any size of the cell phone circuit board, it will be more convenient for you to repair cell phones with different sizes. 2. Choose a cell phone PCB holder that is able to stop or fixed on the table, so it does not move while desoldering or removing BGA chips. 3. Choose a cell phone PCB holder that is selected to be grounded as to prevent electrostatic charge, in this case, you can avoid damage to some sensitive electronic components on cell phone circuit board. 4. Choose a cell phone PCB holder with ESD-Safe material, it's often the best choice for cell phone PCB repairs.   MJ ...

Sometimes front or rea camera can't be used normally, it is a common problem of the mobile phone. If the same problem is found on your iPhone 6S, how should you diagnose and repair it? 1. Rear Camera Repair First, we take out WUXINJI schematic diagram  and read the power supply circuit diagram of iPhone 6S. There are three circuit of power supply in total: One of the circuit is 1.2V PP1V2_CAMERA from the power supply IC, the 1.2V power supply was sent to rear camera interface J3200 through inductor FL3201, if the voltage is not sent to the iPhone 6s rear camera interface, it is generally caused by FL3201 corrosion, use jumper wire to do short connection will solve the problem. The second circuit is 1.8V from the IC power supply, 1.8V power supply was sent to FL3220 rear camera interface through inductor FL3220, and inductor 3220 is easy to get corrosion damage so that 1.8V is not able to be sent to rear camera interface, use jumper wire to do short connection wil...

Have you ever forgotten your cell pone password after you change again and again? Or you are not able to remind the password since it hasn't been used for a long time? Don't panic! In this article, you will find the answer for how to bypass the cell phone password! 1. Unlock by Google Account First,  you should be sure that your cell phone has been setted and signed up with google account; Input any password when system reminds you have typed the wrong password, try it again 30 seconds later. Then Put it again; The system shows Forgotten the password, touch on forgot the password; Enter your gmail user ID and password to sign in, you need to make sure the phone is connected to the internet; 2. Reset Phone to Factory Setting Make Phone Power off, you need to press power button and volume down (key and home/camera button) simultaneously. (If your mobile device does not have camera/home button then press power button and volume down button simultaneous...

iPhone 6s signal part is mainly composed of baseband CPU--U_BB_RF, baseband power U_PMU_RF, intermediate frequency U_WTR_RF, 2G antenna switch ULASM, 3G/4G antenna switch UHASM, preamplifier UDIVA_RF, 2G power amplifier U2GPA_RF, 3G power amplifier, 4G power amplifier UHBPA_RF and power supply U_QPT_RF. The main faults of the iPhone 6s signal are as follows: - Completely no signal we should make clear the baseband is starting properly, then input *#06# in the dial-up interface, if the iPhone 6s screen  does not appear a string of numbers (IMEI code) which means that the baseband does not start properly, for some iPhone devices, you can see IME but if the iPhone screen does not display the IMEI after entering *#06# on the dial-up interface, it also means that the baseband doesn't start normally, this is usually caused by the baseband CPU false welding, or it's also possible that baseband power is false welding, the solution is to replace new iPhone 6S CPU  or baseband pow...

Today, we are going to talk about iPhone 7 7 Plus no signal issues. Actually, if your iPhone 7/7P shows no signal, then you can't make the phone calls or sent messages. Unless your iPhone 7/7P is in WiFi coverage, otherwise the iPhone won't be able to contact with others. Here are three types of no signal issues and related solutions. 1. iPhone 7/7P has no signal at all, infinite search. Get into IOS, go to Settings>- General>- About to check whether there is the IMEI. If the IMEI is not displayed on this iPhone, then you need connect iPhone to DC power supply  to check iPhone boot current, and then determine if it has a large current issue. If there is a phenomenon of leakage, then you can fix it with leakage methods; if the current is normal, then you can directly replace the baseband power without test, and then re-install the iPhone baseband CPU. If IMEI is displayed on the iPhone normally, then set up the time （WiFi Automatic settings available）， enter the ...