Troubleshoot: iPhone X failed to boot

Today, we are going to talk about iPhone X problem. This iPhone X is failed to boot,  we confirmed the iPhone display screen and iPhone battery are good, so now we need to check iPhone X motherboard. As we know, the iPhone X logic board is double layer designed, so we have to be patient and be carefully during the repair process.

Firstly, we need to tear down the iPhone X.  Use phone opening tools to disassemble the iPhone X, and then remove the iPhone dispaly screen, disconnect the battery, and then remove the iPhone X motherboard.

Now, we need to separate the folded motherboard, we can put iPhone X motherboard on the SS-T12A heating station, so we can separate the motherboard.

After separating the motherboard, we  need to measure the iPhone X upper layer logic board with DC power supply, the current is abnormal, now we confirm that the faulty is on the iPhone X upper layer.

Use digital multimeter to measure the iPhone power supply voltage of the upper layer, we found that there is no voltage value on C2771 and C2770.

Continue to measure the C2771 , it is normal. Then measure the C2770, the problem was found, the inductor L2770 is damaged.

We need to replace the damaged L2770. Attach the upper layer to the iPhone X PCB Holder, in order to protect the surrounding components for L2770, we need to stick High-Temperature Adhesive Tape in there. Use QUICK 861DW hot air rework station to remove it.

After removement, re-weld the new inductor L2770 to the motherboard, and then measure it again, now the data is normal.

Finally, install the iPhone X, and test it, the iPhone X is turned on successfully after pressing the power button, the trouble has been solved!

Here to get iPhone 7 A10 CPU replacement manual

 Today we are going to replace the A10 CPU, the iPhone 7 A10 CPU is damaged, and it causes iPhone 7 deosn't works properly, we are going to replaceit directly, here is the replacement manual.

Use screwdriver to remove the screws next to the iPhone lightning port, put iPhone 7 on the CPB screen separator for a while, so we can open the iPhone display assembly easily.

After remove the iPhone display assembly, carefully take out the iPhone motherboard.

Put iPhone motherboard under the Trinocular Integrated Microscope, and then apply high temperature resistant tape to the components next to the iPhone CPU.

Use QUICK 861DW hot air rework station to heat the edges of the iPhone CPU, and use graver to remove the glue from the CPU edge.

During this process, please be careful and be patient, because the circuit line on the bottom is easy to damage when you remove the surrounding glue by using blade from bottom to top. The other hand, please don't put the hot air gun at the same place for a long time, we need to move it evenly and constantly, and avoid to heat the iPhone baseband directly. With this way, we can avoid damaging parts because of overheating.

Use thin blade pry in the iPhone CPU, then gently move the blade from right to left, and when moving to the top end, stab the knife in a little bit, then move the direction from left to right to pry the CPU.

After removing the iPhone CPU, we need to clean up the solder pad. Apply the solder paste on the solder pad, heat it by QUICK 861DW hot air rework station, and then clean it with cotton. 

Next is to remove the residual glue using a scraper, and then clean up the remaining glue on the side of the pads and pads

We need to clean up the iPhone CPU. Apply solder paste on the iPhone CPU, and use hot air gun to clean it. Use blade to remove the glue from the CPU and the glue on the side of the CPU, and then clean it again.

Now we need to re-solder the iPhone CPU. Align the QianLi Black BGA Reballing Stencil to the A10 CPU, apply solder paste on it, and then use hot air rework station to heat it for a while to make it dry.

Take out the iPhone CPU, and then clean it up. Apply some solder paste on the iPhone CPU, and then install it back to the iPhone motherboard, and then assemble the iPhone 7.




Press the iPhone power button, the iPhone 7 is turned on properly. After entering the IOS, test the functions on iPhone, the touch functions, the WIFI function, the BT functions and all other function are working properly!

Troubleshooting tips for iPhone 6 Plus WIFI button failure

 In this page, we will talk about the iPhone WIFI button problem. Here is an iPhone 6 Plus with WIFI button failure.  The iPhone 6 Plus WIFI button can't be turned on after dropping, here are some troubleshooting tips for it.

Firstly, rest all functions on iPhone, the 3D touch, camera and Bluetooth functions all are normal, except the iPhone WIFI function, the iPhone WIFI switch can't be turned on, and it’s grayed out. Firstly we try to fix by some simple software solutions, but not working, until we dissemble the iPhone and fix it in hardware aspect. The repair process is as follows.


Tips 1: Restart iPhone 6 Plus.

As we know the iPhone WIFI problem could be caused by the iPhone has software problems or crashed App, restart iPhone can fix many simple software problems.

In order to restart the iPhone 6 Plus, please press and hold the iPhone power button until the slider appears, drag the slider to turn your iPhone 6 Plus completely off, after the iPhone 6 Plus turns off, press and hold the iPhone power button again until you see the Apple logo.

Now test the iPhone WIFI switch, but it's still won't turn on.

Tips 2: Reset network settings

The iPhone network setting problem also can cause iPhone WIFI failure, so we need to reset the network settings.

In order to reset network settings, tap settings-> General-> Reset, and then tap reset network setting.

After resetting, back to WIFI to check, the iPhone WIFI switch still is grayed and won't turn on.

Tips 3: Update IOS

Is it the IOS problem? So we try to fix it by updating IOS. Go to Settings-> General, and tap Software Update on iPhone 6 Plus, the IOS update is available. Because the iPhone 6 Plus can't connect to WIFI, so we going to update it via iTunes.

Connect iPhone 6 Plus to the computer via iPhone lighting cable, and then use iTunes to update the IOS. Unfortunately, the iPhone WIFI switch is still not turn on.

Now we need to disassemble the iPhone 6 Plus to check inside of it.

Tips 4: Disassemble the iPhone 6 Plus

Use screwdriver to remove the screws next to the iPhone lightning port, and then put iPhone on the CPB screen separator, after a while, we can disassemble the iPhone smoothly.

Tips 5: Repair  iPhone 6 Plus

Remove the iPhone motherboard, and then use QUICK 861DW hot air rework station to remove the iPhone WIFI IC, we found that there are many pins of the iPhone WIFI solder pad are dropped, this is the real problem, we need to re-fill the pins.

Clear up the solder pad, re-fill the dropped pins, and then apply the green UV oil to fix them. Install the iPhone WIFI IC back to motherboard, and then install the iPhone 6 Plus.

Finally, power on iPhone and test it, now the iPhone WIFI switch can be turned on smoothly, and the iPhone WIFI function is working properly. Continue to test the other functions, all works well. The repairs end!

Troubleshoot: iPhone 7 has black screen issue after dropping

The iPhone 7 screen doesn't display, it has black screen issues, how to troubleshoot it? The screen issue is one the most common problems for the iPhone,  there are many solutions for fixing this black screen issue.  Let's troubleshoot this iPhone 7 black screen issue.

The iPhone accidentally drop into the ground, after pick it up, the iPhone screen is good, but it doesn't display after booting.

Let's try some software solutions first, if the software solution doesn't work, then we should try hardware solution.  After trying the software solutions ( Force restart/ Update IOS/ DFU restore),  the iPhone screen still is black, now we need check iPhone motherboard.

Disassemble the iPhone 7 , remove the iPhone display screen, and then take out the iPhone motherboard, connect it with the DC power supply to test the iPhone boot current, the boot current jumps to around 350mA, and then turns downs and restart.

Because the iPhone 7 screen is damaged by dropping, so we suspected it's caused by virtual-welded iPhone Nand flash or damaged system.

Connect iPhone to the computer, and then brush it with iTunes, the iTunes reports unknown error 4013. The error 4013 is related to iPhone Nand flash problem.

Use QUICK 861DW hot air rework station to remove the iPhone Nand flash, and then measure the diode data of the iPhone data cable that communicates between the iPhone Nand flash and the CPU, the data tested is normal.

Install the iPhone Nand flash to the JC P7 Nand programmer; the data of iPhone Nand flash can be read normally, which means the iPhone nand flash has no problem.

As we know, the iPhone baseband CPU problem also will cause this problem. Put iPhone motherboard under the microscope to observe, no components are missing. Directly remove the iPhone baseband CPU, clean up the solder pad, and then re-weld the iPhone baseband CPU to the iPhone motherboard.

Assemble the iPhone 7, press the power button, after few seconds, the Apple logo appears normally, and then the iPhone enters IOS system.

Testing the functions on iPhone, the touch function, WIFI function, camera function and other functions all is working. The repairs end!

iPhone IC list: the IC can be replaced on iPhone motherboard

When the iPhone has hardware failure, generally we need to check iPhone motherboard, and then we will find that some iPhone chips or components were damaged. At this time, we can try to repair it, but some IC or components ware damaged, or it's hard to repair, so we can repalce it with the new one.  Here we can get an iPhone IC list, so than we can know what ICs that often needs to be replaced on the iPhone motherboard

Common replaceable Chips For iPhone 6/6 Plus
IC Name	Number on the PCB board	Model
PMU	U1202	338S1251-A2
USB charge IC(U2/Tristar)	U1700	1610A2
Touch screen control IC(Black)	U2402	343S0694
Touch screen control IC(White)	U2401	BCM5976
WIFI module IC	U5201_RF	339S0242
Display IC	U1501	65730AOP
Backlight IC	6:U1501 / 6P:U1502 U1580	LM3534TMX-A1  DY
Baseband PMU	U_PMICRF	PM8019
Big RF IC/ Mid Frequency IC	U_WTR_RF	WTR1625L
Speaker Amplifier/small Audio	U1601	338S1202
Audio IC/ big audio IC	U0900	338S1201
Flashlight LED IC/ Flash Control IC	U1602	64A1
Fingerprint Boost IC	U1503	3638
Backlight Boost Diode	U1501	NSR0620P2XXG

Common replaceable Chips For iPhone 6S/6S Plus
IC Name	Number On the PCB board	Model
Power management IC	U2000	338S00122-A1
USB charger IC(U2/Tristar)	U4500	1610A3
WIFI module IC	U5200_RF	339S00033
Display IC	U4000	65730AOP
Backlight IC	6S:U4020 / 6SP:U4020 U4050	3539
Baseband PMU	U_PMU_RF	PMD9635
Big RF IC/ Mid Frequency IC	U_WTR_RF	WTR3925
Speaker Amplifier/small Audio	U3800 / U3700	338S1285
Audio IC/big audio IC	U3500	338S00105
Fingerprint Boost IC	U4040	3618J2
Flashlight LED IC	U3300	64A1

Common replaceable Chips For iPhone 7/7 Plus
IC Name	Number on the PCB board	Model
PMU	U1801	338s00225
USB charge IC(U2/Tristar)	U4001	610A3B
WIFI module IC	WLAN_RF	339S00199
Display IC	U3703	T1G2C1N31
Backlight IC	7:U3701 /7P:U3701 U4601	61A2Y1L
Baseband PMU	BB PMU_RF	PMD9645
RF IC/ Mid Frequency IC	XCVRO_RF	WTR3925
Speaker Amplifier/small audio	U3402 U3502 U3301	338S00220
Audio IC/big audio IC	U3101	338S00105
Fingerprint IC	U3702	3638J2

 

How to best fix iPhone 6 error 4005?

Apple iPhone iTunes error problem is common, now here is an iPhone 6 with unknown error 4005 problem, how to best fix this problem? Generally, we can try some simple solutions first, if it's not working, then we can check the hardware aspect.

Some simple solutions (software aspect):

-  Force restart iPhone 6
- Make sure the iTunes is latest version
- Try another lightning cable or USB port

After trying this solutions, the iPhone 6  still has unknown error 4005. 

Next, disassemble the iPhone 6.  Use phone opening tools to disassemble the iPhone 6,  and then remove the iPhone motherboard.

Now use digital multimeter to measure the iPhone Nand flash, power supply 3V, iPhone power supply C0604 1.8V, CO603 1.2V and C0625, all voltage tested are normal. Next measure the resistance value for iPhone Nand flash, but it's still normal.
Use QUICK 861DW hot air rework station to remove the iPhone Nand flash, and the put iPhone motherboard under the microscope, re-welding the pins on the iPhone Nand flash, and then solder the iPhone Nand flash back to iPhone motherboard.

Next assemble the iPhone 6, connect iPhone to the computer, and then use iTunes to restore it, now it works, there is no unknown error code.


Testing the functions on iPhone 6, they all works properly. The iPhone 6 unknown error 4005 has been fixed!

Troubleshooting Tips: unknown error 9 occurred on iPhone XR

There is an unlnown error 9 occurred on iPhone XR when we try to resore it with iTunes,  how to fix it? Here are some troubleshooing tips.

Fristly, use iTunes to restore the iPhone XR again, it's still failed to restore, and reports unknown error 9. Now, we can try the following troubleshooing tips to fix this problem.

1. Force restart iPhone XR

If this unknown error 9 is caused by some simple software problems, then restarting is a good solution, because the most of simple software problems can be fixed by restarting.

In order to force restart iPhone XR, please quickly press and release the iPhone Volume Up button, and then quickly press and release the iPhone Volume Down button, at last, press and hold the iPhone power button  until the Apple logo appears, and then release.

After restarting the iPhone XR, connect it to the computer to test it again, if the unknown error 9 still exist, then you should try another solutions.

2. Check connections between iPhone and computer

If the connection between the iPhone XR and the computer is fragile or incomplete, then it will cause the iPhone XR to fail to restore and report the error code.

In order to avoid this case, we need to check iPhone lightning cable and USB port. Make sure you are using an Apple lightning cable with good quality, try different USB port, or try another computer.

After you try these methods, if the iPhone XR error 9 still exists, then you should try another solution.

3. Reset all Settings

The setting problem also will cause iPhone got an unknown error during the restore, if the iPhone XR has some invalid settings, it will cause iTunes or access to deny the computer programs or other apps. We can try to fix it by resetting all settings.

In order to reset all Settings, please go to Settings-> General -> Reset -> Reset all settings.

After resetting, please re-restore it, if it still not working, then try next solutions.



4. Check iTunes version

As we know, if we want to use iTunes to update IOS or restore iPhone, the first thing is that we need to update the iTunes to latest version, so we can make it works smoothly.

Please open iTunes on the computer, and then check it if it's the latest version. If not, please update it to the latest version, and then use it to restore the iPhone XR again.

If the iPhone XR is still unable to restore with the latest iTunes version, then please try another solutions.

5. Contact Apple Care

If all of above solutions are not working, and you have no ideas for it, then you can contact Apple Care for help. They will help you to fix the iPhone XR with their professional phone repair tools and skills.