Solution for iPhone 6S Plus display and touch fault

While you happens some screen fault, you may be craze about this fault. At least, i can't stand it.

Fortunatelly, i have learnt some phone repair knowledge, then i can fix it by myself, then it also can be useful for doing a phone repair business.

iPhone 6S plus touch IC is on the touch screen, so there no need extra operation for phone motherboard, it will be easier for the next repair procedure.

By checking WUXINJI schematic diagram, we can see that the power supply of the display and touch screen is supplied by U4000 and power C--U2000.

The power IC provides a 1.8V power supply, and U4000 provides 5.7V to 5.1V voltage. As shown in picture 1-1.

 picture 1-1

The inductor FL4200 FL4205 FL4207 FL4208 FL4209 FL4210 is easy to corrode, resulting in no indication, no touch. If you encounter the same condition, short connection can solve the problem.

If there is no light and no display, first you need to do is to install the iPhone 6s plus screen (Since it is more troublesome to install screen for measurement, you can also short connect by jumper wire as the green line remarked in picture 1-2, then use Fluke 15B+ digital multimeter to measure the IC output voltage 5.7V on single logic board directly.

picture 1-2

If there is no 5.7V on the components as shown in picture 1-3, it means that the display screen power supply IC--U4000 is damaged, the solution is to to replace a new U4000. If there is 5.7V, you need to check the short inductance FL4200 FL4205 FL4207. If there is touch failure condition, check and short connect FL4208 FL4209 FL4210.

picture 1-3

While doing the corresponding deal as followed our guiding, you will get the right result.

Solution for iPhone 7P Charging Fault

Most of iPhone 7P charging fault are related with the charging port, or the phone battery, if you don't know how to fix the charging fault, just directly replacing it. If it still keeps invalid, you may need to find a phone repair shop.

Charging station ask a disassemble, along with the professional skill, so you may be interested what we will shared.

Check iPhone schematic diagram on WUXINJI Dongle, 5V charge voltage PP5V0_USB  sent by the tail-plug interface，one circuit is sent to iPhone charge IC, one circuit is sent to iPhone USB control IC. The repair method is as follows.

Disassemble the iPhone 7 Plus with phone disassemble kits, remove the iPhone motherboard.

Measure the 5.0V voltage (PP5V0_USB) next to the iPhone charging IC with
Fluke 15B+ Digital Multimeter to check whether it exists. If not, then you need to replace the new iPhone tail plug flex cable. If yes, continue to check.

Measure the 5.0V voltage (PP5V0_USB) next to the iPhone USB control IC with multimeter to check whether it exists. If not, then you need to use QUICK 861DW hot air rework station to solder the jump wire from 5.0V voltage (PP5V0_USB) next to the iPhone charging IC to 5.0V voltage (PP5V0_USB) next to the iPhone USB control IC. If 5V is exist， then you need to replace the iPhone USB control IC and iPhone charge IC.

If you don't have enough tools to repair it,  maybe you can borrow it from your friends, or purchase it on online shopping WEB.

Two solution for iPhone 5SE Circuit Fault

Fault description: iPhone 5SE occurred turning on fault and leakage.
Possibility reason: phone CPU problem or battery short circuit.

According to our ever experience, we doubt there mostly exist circuit problem, which means we need to disassemble it and check the current by DC power supply, like the following PIC shown:

picture 1-1

The battery positive voltage VBATT is first sent to the charging IC-U2300, and the charging IC-U2300 outputs the main power supply VCC_MAIN (same as the battery positive voltage value) to the main power supply U2000 and other related circuits.

The situation is divided into the following:

1. The current is large when supplying power, this situation is usually caused by the positive voltage of the battery or the main power supply, which has short circuited parts. The large current can be quickly found with the rosin method. How to operate: At first, use digital multi-meter to measure the battery positive pole and the main power supply to the ground resistance value, find out the short circuit parts. Use rosin to smoke the iPhone SE main board into white color, add voltage in the short circuit parts, you have to notice that the voltage must be added to the short circuit parts, the voltage is gradually increased from zero, after the short circuited parts is supplied power for a while, it will heat and turn into different color, then you can find the specific components immediately.

2. The iPhone SE device has no response after turning on, first measure whether the main power supply of U2300 is there, if not, you need to replace U2300, if the main power supply is normal, then it means the problem is from the power IC or CPU.

3. The current is small and iPhone is unavailable, measuring whether the voltage of the parts as shown in WUXINJI schematic diagram is normal, as shown in 1-2, if yes, you need to replace the clock crystal Y0600, check and weld several pull resistance of bus circuit will cause small current and iPhone unavailable, these resistance must be replaced instead of short connection, if the above problems are excluded, it should be the iPhone SE CPU  problem, you can install a new CPU to solve.

Picture 1-2

How to handle iPad Air2 Reboot Fault while Blurred Screen

Fault description: iPad Air2 happens blurred screen while reboot automatically

Repair iPad will be easier than iPhone, as of its body, don't ask too precision tool. But most of us will choose to purchase a new one to replace the older,  because the price of iPad are sold cheaper than iPhone device.

While the repair fee also are cheaper, it is okay, we need to fix it firstly.

Connect the iPad 2 on computer and reflash by iTunes, it reports error 4013, we judge the problem comes from flash memory.

Use corresponding iPad opening toolkit to disssaemble the iPad Air2 and take off the motherboard, then put the motherboard on iPad PCB test fixture for the next repair operation. It is found the iPad NAND chip was repaired before, so we remove the Nand chip and reflash again, the error code is reported again. So we are going to directly repair flash memory.

After the flash memory is installed, it's normal when reflashing again, invalid SN is reported.

If the invalid SN is reported, it basically means flash memory has no problem, install the iPad Air2 NAND chip and turn it on directly.

Generally, blurred screen and reboot is caused by the flash memory problem, if you encounter the similar problems in the future, directly repair flash memory.

This NAND chip was repaired before, so we estimate the flash memory is false welded when blowing with hot air gun. In the past, the customers who had iPad Air 2 NAND flash memory expansion said that it did not take long to encounter new problem. So you need to be very careful on iPad Air2. The NAND flash is very close to CPU flash , the last repairman was prying from the inside when expanding NAND flash memory, we usually cut the shield from the outside and pry from the outside, this will be more safe.

iPhone 6S button fault as of IC problem

More use, easier fault. Fortunately, it is just a little part, no worry about it.

According to the topic, you may have known what we will talked. Got this phone, just like spending out lunch time normally, we have met so many fault like this. Ok, let us prepare our tool to fix it.

Put iPhone 6S on the WL Aluminum Alloy Pad, and then use phone opening tools to disassemble the iPhone, take out the iPhone motherboard.

Measure the resistance of J4700_3# with Fluke 15B+ Digital Multimeter, it is normal. Put iPhone motherboard under the 3.5X-90X Stereo Zoom Microscope to check, we found the iPhone power IC was replaced by other phone repair man. Measure its voltage, it only has 0.5V, and the voltage of BUTTON_VOL_UP_CONN_L volume up button signal is pulled down. 

16-11-1

Based on our repair experience, mostly this failure is caused by damaged iPhone CPU, so replace the iPhone power IC is useless. 

BUTTON_VOL_UP_L lower voltage, it has no external pull resistance, it is pulled directly through the CPU internal. Borrow PP3V0_TRISTARUSB controller 3V string the resistance of 1K, so that the voltage is pulled up to 1.6V. 

Assemble the iPhone to test; now the iPhone volume up button can be used normally.

16-11-2

Fix iPhone 6 with Professional Phone Repair Tool

Got the problem iPhone 6, we knew it was much intractability as it was described many faults occurred, like battery, charging IC and  PCB motherboard .

We doubt there seems to happen a secondary damaged, if it was just repaired for one time, it won't happen so many fault.  Then we have got it, we should be responsible for it, with out professional phone repair tool to fix it, cure it, keeping your step in our tutorial.

1. Use a Fluke digital multimeter to measure the voltage of (C1408, C1700) USB were given to U1401 charge tube and U1700 (U2), the both 5V are normal

2. Respectively remove the U2 and charge tube, measure the bottom voltage to see whether the iPhone 6 motherboard has broken cables, the result shows that the two chips are all normal.

3. Replace the two new chips and charge to have a test, the result is same.

4. Connect the iPhone 6 with computer, the battery life shows no data on Ace assistant, this situation often happens on iPhone 6 and iPhone 6P, basically it's caused by the problem of CPU to the charge tube battery detection circuit, also the solutions are different.

5. By checking 2.2K resistance(remove R0302 and R0303 from junk motherboard) on WUXINJI schematic diagram, then connect the two resistors together. One end receives the main power supply, and the other end is grounded, and solder a jumper wire to charge tube G1 pin in the middele of the two resistors.

6. Personally, I think this method is troublesome, there is another simple way to use: add a 10K resistance (R0307 or R0310) on C1700(next to U2), which can be directly welded to one end of the C1700 PP3.0V, the other end can be welded to the charge tube G1 pin, then use green oil and UV light to solid.

7. Install the iPhone 6 device to test, charging function is normal now.

That is all the detail process, if you are interested in DIY, maybe you can try to do it by yourself, any tools needs pls contact us.

Handle iPhone 6S Touch Panel Fault Effectively

In some case, we try our best to avoid repairing again. But we can't refuse what we received,  customer is God. But as a professional repair man, no matter what met, we also need to check it carefully, to avoid this phenomenon happens again.

We got a iPhone 6S, question Phone, from one of our client. They DIY it by himself, but it seems the process didn't get a good result. Okay, let us start it.

Following the detail fix process:

Disassemble the iPhone by phone opening tools, remove the iPhone motherboard, and then measure the diode data for iPhone touch screen with Fluke 15B+ Digital Multimeter, we found the iPhone touch screen synchronized pin is short circuit. A capacitive filter on the side of the socket, a capacitor directly connect to CPU, we can check iPhone schematic diagram on WUXINJI Dongle.

Now, we need to remove the capacitor with Precision Titanium Alloy Tweezers, after movement, measure it again, it still is short circuit. Now, we need to remove inductance,

Use QUICK 861DW hot air rework station to remove the inductance, and then measure it again with multimeter, short circuit phenomenon still exists.

The socket is short circuit, the capacitor is short circuit, and the inductance also is short circuit, we can't fix it by borrowing power from other place.

So there just existing one way to fix it, dangling touch, we test it and found it can work normally, it is amazing, thanks for our ever experience.