Repair Guide: iPhone X won’t turn on after dropping(error 56)

 The iPhone X won't turn on and reports unknown error 56, why is that? The iPhone 6 accidentally fell into the ground, and then it can be turned on as usual, according to our repair experience, we think it's the problem of the iPhone motherboard. 

Conect iPhone X to the computer by iPhone lightning cable, and then use iTunes to re-flash it, the iPhone is failed to flash, the iTunes reports unknown error 56.

Disassemble the iPhone X by phone opening tools, take out the iPhone X motherboard. With the help of the PPD 120XL iPhone X pre-heating platform,we can separate the iPhone X motherboard smoothly. 

As we know,    the iPhone X is connected by 2 pieces motherboard via a middle column, so the pins are easy to lose because of dropping. Now, it's possibly the pin from the NFC chip to the iPhone CPU that was dropped off.

Check iPhone schematic diagram via WUXINJI Dongle, it's surrounded by ground lines, and the 6 useful pins was dropped off.

The ground lines are no need to fill, we just need to fill these 6 useful pins, we can check iPhone motherboard under the Stereo Zoom Microscope. These all are the signal line of the NFC chip, so when we restore iPhone by iTunes, it reports unknown error 56.

Next we need to plant the tin in the middle column by QUICK 861DW hot air rework station, and then re-weld the AP part.

After installation, assemble the iPhone, and then re-flash it agian, now the flash process goes well. 

After entering the IOS system, test the function on iPhone X, all functions tested are normal.

Step By Step to fix iPhone 7P front camera failure

 Last week, we received an iPhone 7 Plus to repair, the problem is that this iPhone 7P front camera is not working, it won't take photos, just shows black. We fixed it step by step, here is the repair process.

Step 1

Get into IOS system and test the iPhone camera. The iPhone rear camera, flash and other functions are all normal, but the iPhone front camera is not working.

Step 2

Use phone opening tools to disassemble the iPhone, and then remove the iPhone motherboard.

Step 3

Put iPhone motherboard under the Stereo Zoom Microscope to observe,  we found the repair traces of front camera J4503 base. It means the iPhone 7 Plus was repaired before. As shown in picture 1.

Step 3 

Measure the iPhone motherboard by digital multimeter, the data tested is normal.  When measure the voltage of the 2 groups of I2C that were repaired: (R4810) I2C_NH_SCL_CONN and (4811) I2C_NH_SDA_CONN, we found R4811 resistance has no voltage, but it has value when trigger. The circuit diagram we can check on WUXINJI dongle.

Step 4

Now we can judge that R4811 is damaged, so we need to replace it. With the help of the QUICK 861DW and tweezers, we remove the incoming panel and replace the two pull-up resistors.

Step 5

 

Assemble the iPhone 7 Plus, power on iPhone 7P, and then test it, the iPhone front camera works perfectly.

iPhone 6 failed to boot and no backlight—Fixed details!

The iPhone 6 is very old version, and it's reasonable to have some problems. Here is an iPhone 6 with not turning on problem and no backlight. Luckily, we can fix it, and here is the fixed details. 

Use phone opening tools to disassemble the iPhone, and take out the iPhone motherboard to the oberve it,  we found that the top right corner screw column of the iPhone CPU is missing, the iPhone motherboard has been dug and welded jumper wire.

  

Connect iPhone motherboard to the DPS DC power supply to check the current condition, we found that the iPhone current was above 200mA, then dropped and stayed around 150mA. According to the iPhone boot current working process, we analyze that the iPhone isn't turned on when the current was above 200mA, this failure is usually caused by iPhone display and backlight circuit. Use digital multimeter to measure the grounding resistance value of the display and backlight circuit.

The resistance value measured is normal, so we replace the iPhone display IC, but the problem still the same after replacement. Now, we need to replace the iPhone backlight IC, after replacement, we found the iPhone boot current jumps normally. Install the iPhone display assembly and test it, the iPhone can be turned on, and the backlight also is normal. However, when the iPhone came to unlock the interface, the iPhone display screen suddenly became dark and then completely black, the iPhone backlight didn't work anymore, and the iPhone boot current stays at the same value as before.

Seems it's the iPhone backlight problem, and it causes iPhone can't enter the IOS smoothly. Replace the several iPhone backlight ICs, but it is still not working. Measuring the voltage with digital multimeter, the working condition of the iPhone backlight all is normal, only the voltage of backlight boost 17V are not up to the normal value. Check iPhone by the light, we can see that the iPhone screen stuck in the boot interface.

Replacing the iPhone backlight IC is useless, so we are going to replace the iPhone backlight IC, iPhone diode tube and inductors.

After replacement, the iPhone was normal at first, but it didn't work the second time it turned on. Check iPhone schematic diagram via WUXINJI Dongle, we found there are many wires under the screw column, which includes the wire of the iPhone backlight circuit.

Put iPhone under the Stereo Zoom Microscope, dig the iPhone motherboard，we found the cathode wire of iPhone backlight is cracked, solder the jumper wire on it, and then apply some green UV oil.

Connect iPhone motherboard to DC power supply to test it, now the data tested is normal. 

Insall the iPhone motherboard, connect iPhone battery and iPhone display assembly, and then press the iPhone power button, the white Apple logo appears as usual, after few seconds, the iPhone is enter the IOS systems smoothly. 

Using it for 1 day, the iPhone 6 is working properly, and all functions tested are normal.

Solved: iPhone 7 Plus unable to enter IOS and report error 9

 Here is an iPhone 7 Plus accidentally dropped into water, it still can be used normally when we clean up the water, however, it can't be used after a day. The problem is that after press the iPhone power button, it always auto restarts. When we re-flash it with iTunes, it reports unknown error 9. We have to solve it. 

According to our experience,  the iPhone Nand flash and iPhone logic epprom IC all can cause this problem. Now, we need to disassemble the iPhone 7 Plus first.

Use phone opening tools to disassemble the iPhone 7P, take out the iPhone motherboard. Use digital multimeter to measure the power supplu of the iPhone Nand flash, the  3V, 1.8V and 0.9V all are noraml.  

Check iPhone motherboard under the Stereo Zoom Microscope, we know that the iPhone Nand flash and iPhone logic epprom IC didn't been repaired, but the iPhone baseband part did. Leave it alone, now we try to fix it by replacing iPhone Nand flash, after replacement, it still reports unknown error 9, then it may problem of the iPhone logic epprom IC. Directly replace the iPhone logic epprom IC, after replacement, it still reports unknown error 9.

As we know, when the resistance value of the two resistors that connected to the logic epprom IC is too large, it will also reports error 9, try to replace these 2 resistors. Remove the iPhone logic epprom IC and the resistors that connected to it, and then with the help of the QUICK 861DW hot air rework station and Titanium Alloy Tweezers, we replace all of them.

After replacement, re-flash the iPhone, now the process bar is running normally, which means the iPhone baseband part is no problem, the iPhone is basically repaired. 

After the flash done, press the iPhone power button, now the iPhone 7 Plus can be turned on smoothly, and it is entering the IOS system successfully, all functions on iPhone 7 Plus tested are normal.