Troubleshoot Tips: iPhone 6S Plus no sound issue

 We received an iPhone 6S Plus to repair, the issue is that there is no sound  when the iPhone plays music, but after insert the earpiece, we can hear sound. What's going on?  Here is the troubleshooting tips for it.

The first step is to judge the fault, if there is no speaker voice when playing music on iPhone, generally the fault is caused by iPhone audio amplifier chips. There are 2 Audio Power Amplifiers: U3700 and U3800.

Which chip is out of problem? The previous test has said that the vibration function is not normal. The vibration function is managed by U3800 chip. Therefore, we remove the U3800 chip to measure the ground resistance of the chip pad. It is found that the E7pin I2S_AP_TO_ARC_MCLK  ground resistance is infinitely great.

In WUXINJI schematic diagram, it is known that the signal passes through the R0921 resistance to the iPhone 6s Plus CPU.

In the measurement, it is found that the CPU solder joint is broken down to the R0921 resistance layer. It is not easy to dig the route on the plate layer, so we try to borrow the 12S_AP_TO_CODEC_MCLK signal of the audio IC chip, use QUICK 861DW to solder jumper wire from the R0920 resistance to the R0921 resistor.

After finish the above step, assemble the iPhone, get into IOS to test, now we can hear sound normaly from the speaker , the vibration and recording also works good. The repairs end!

Best Solution--iPhone 6 camera get stuck when turn it on

A customer sent an iPhone 6 to us to repair, the fault described is that the iPhone 6 rear camera sometimes won't turn on, and there is a vertical bar when take photos. According the repair experience, first we measure the diode data of rear camera with Fluke 15B+ Digital Multimeter.

When we measure the diode data for the 34th pin, we found it unstable. Sometimes more than 300, sometimes more than 500 (The normal resistance is about 500). Open WUXINJI Dongle to check iPhone PCB schematic diagram, we know that this pin is 2.85 power supply pin.

This 2.85 power supply pin is converted from U2301.

Base on the above conclusions, we suspect that this could be caused by a 2.85V conversion tube virtual weld.  Gently shake the conversion tube with Precision Titanium Alloy Tweezers; The conversion tube has fallen off. We can check it under the VGA Camera 7-45X TrinocularStereo Microscope

Now, replace a new conversion tube. And then turn on iPhone to test, now, when you turn on the camera, it won't get stuck. The iPhone rear camera can be turned on smoothly.

Troubleshooting tips for iPhone X Abnormal problems

Today, we will share some troubleshooting  tips for iPhone X abnormal problems. Such as  iPhone X battery runs out quickly, iPhone X screen burn in, paint off on iPhone X frame, green line on iPhone touch screen and so on.  In the page, we will provide some troubleshooting  tips from software aspect.

1. iPhone X battery runs out quickly

After disassemble iPhone X with JM-9102 Disassemble Tools, you will found it has two batteries. However, it doesn't mean the iPhone X battery can be used for a long time, because some apps can impact battery life on your device. To find out which apps are consuming the most power, open Settings>Battery and you will see a list of apps that tells you which ones are the greediest. You can then choose to prevent those apps updating in the background or from using mobile bandwidth, which should help extend battery life.

Also, here are some tips for save iPhone battery life, turn off Location Services (Settings>Privacy>Location Services) and vibrate mode and notifications, adjust the iPhone brightness, switch on Settings>Battery>Low Power Mode, enable AirPlane mode.

2. The iPhone X screen has no response when it in cold

When the phone is in a cold environment, it will appear to touch no response, automatically switch vibration mode, and even automatic power down. If your iPhone X encounters this issue, please update it to latest IOS. Check which version of the IOS you are running in Settings>General>Software Update.

3. Green line appears on screen

Some iPhone X users reports that there is green appears on iPhone screen, this affects the visual effects of the iPhone X. Try to update your iPhone X to latest IOS, because Apple always use IOS update to solve many issues. If it is not working, then maybe the iPhone X need to be repaired, please send it to Apple.

4. Reboot iPhone X

Although rebooting the iPhone is not the way to do everything, but it is definitely a good way in many issues, it is no exception for fixing iPhone X issues. As we all know, iPhone X has an obvious difference from the previous iPhone, which is without iPhone home button. So, the method of reboot iPhone X also has some change.

Quickly click and release the Volume Up button.

Quickly click and release the Volume Down button.

Press the Side button (sleep/wake, on/off), until the Apple logo appears.

5. Reset iPhone X

If rebooting iPhone X does not solve the issues, then you can try to reset iPhone X. Before you reset your iPhone, you'd better back up your phone first. Go to Settings>General>Reset.

4 Steps To Fix iPhone 6 Won’t Turn On Issue

The iPhone 6 has been dropped heavily, and then the iPhone won't turn on and overheating. Now we need to repair it step by step.

Step 1

Disassemble the iPhone 6 by JM-P01 Essential Toolkit, take out the iPhone motherboard and measure it with DC power supply, it shows large current when booting, about 1300mA.

Step 2

The boot current shows about 1300mA, which is abnormal. Put the iPhone motherboard under a VGA Camera 7-45X Trinocular Stereo Microscope to observe it carefully, we found the culprit on the motherboard. There is a capacitor has been penetrated, which caused the iPhone to turn on with an abnormal large current phenomenon.

Step 3

Now, we've decided to dismantle this capacitor. With the help of Hot Air Gun and Precision Titanium Alloy Tweezers, we succeeded in tearing down this capacitor. Using Fluke 15B+ Digital Multimeter to measure it, the diode data shows more than 300, it is normal. This circuit is iPhone Nand flash power supply 3V, PP3VO_NAND short circuit will causes iPhone won't turn on, and the boot current up to 1000mA.

 

Step 4

After removal, measure it again with 1503D+ DC power supply, the boot current is normal now. Install the iPhone well, and the press the iPhone power button to turn it on, now the iPhone 6 can turn on normally and smoothly into IOS.

DIY FIX: Backlight damage causes iPhone 6 won't boot

 Today, we will share a iPhone repair guide that how to DIY fix backlight damage causes iPhone 6 won't boot. When we supply power to iPhone 6 with C48 MFI USB Cable, the iPhone always shows black screen. Let's learn to diy fix it!

Connect iPhone to DC power supply, we find current 80mA circularly run while connecting and triggering, so maybe it's USB damgage cause I2C short circuit during charging process, first remove the iPhone 6 motherboard and take the USB off, but it's still the same as before, then we measure the I2C resistance and power supply! It is found that the I2C 0SCL is in a short circuit state. As shown in picture 11-10-1.

Since it's short circuit, it means the connected chip is damaged, the connected chips have display, backlight, main power supply USB and the iPhone 6 CPU.

First observe with VGA Camera 7-45X Trinocular Stereo Microscope, it is found that all the backlight diodes are burning and discoloring.

Then remove the backlight first, it does not short-circuit. The trigger current is normal, so continue to replace the 3 piece of iPhone backlight chips.

According to our past experience, if the large inductors gets discoloring, the large inductors with connected iPhone backlight IC would also have problems, so we replace them together. As shown in picture 11-10-2.

Measure it again with DC power supply, now the current is back to normal.  At last, instal the USB, and turn on iPhone, it runs smoothly and successfully. Keep going to check other functions, all is fine. The repairs end!