Slove iPhone 6 trouble from PCB circuits screws disconnected

Customer said  accidently used the 1mm longer screw for the buttom left hole broke some traces.
IPhone 6 displays nothing when turned on. Customer said that the screw hole is twisted through.

how to fix?

step:

This iPhone 6 has been fixed before, but the problem remains the same. After tearing it down, we find that three screws are twisted deep. The problems are no backlight, no display and no ±5.7V power supply of screen. Observing under microscope, we find that the four circuits under those screws are disconnected, as shown in picture 6-37.

Picture 6-37

One of the four circuits is the open signal LCM_TO_CHESTNUT_PWR_EN of display power supply chip. This signal connects power supply chip U1202, as shown in picture 6-38.

Picture 6-38

The signal LCM_TO_CHESTNUT_PWR_EN connects display power supply chip U1501, as shown in picture 6-38.

Picture 6-39

The signal LCM_TO_CHESTNUT_PWR_EN connects display socket J2019 through the inductor FL2035, as shown in picture 6-40.

Picture 6-40

After measuring, display socket has no diode data, which suggests that it is disconnected. We have to jump a wire, as shown in picture 6-41.

Picture 6-41

After it can display, we measure other function and find that the receiver has no sound, but the diode data to ground of receiver is normal. Remove the audio chip (U0900) and measure the diode data. We find that pin C9 is disconnected. Pin C9 is connected to CPU (U0201), as shown in picture 6-42.

Picture 6-42

Because CPU has not been fixed before, we guess that the disconnection of the circuits under screws causes the problem. Find a bare motherboard and scratch its surface (called grinding, as shown in picture 6-43). Thus we know that the second layer (arrow in picture 6-44) under screw causes problem.

Picture 6-43

Picture 6-44

Next we jump a wire from audio chip pin C9 to the point that we find by grinding. At last, we paint UV Solder Resist  to solidify it, as shown in picture 6-45.

Picture 6-45

We skip other process of jumping wires, 10 wires in total. Turn on iPhone and it displays normally. Trouble is removed.

Comments

Post a Comment

Popular posts from this blog

Slove iPhone X Won't Turn On

Image
Customer delivered a iPhone X and described the fault is not to boot after the phone drop accidentally. It reports error 56 when restore the iPhone X. How to repair this fault? Because iPhone X is the two board connected through the middle column, it is easy to drop the point. It may be that the solder points from NFC chip to the CPU part have fell off. Take apart the iPhone X by iPhone Screwdriver Repair Tools , take the upper board off the main board, when separate the main board we see a row of points have fell off. Picture 19-3-1 Look at the location map on WUXINJI dongle , it is surrounded by a ground wire, in fact, there are 6 useful points dropped. The ground wire does not need to be filled, the 6 useful points are added by professional phone welding tools. These are the signal wires of the NFC chip, so the iPhone X would report error 56. Picture 19-3-2 Then the tin of the middle column is repaired by iPhone X BGA reballing stencil , and the AP part is welded bac
Read more

Setup and install the zxw tool Dongle Wizard

Image
So, you recently purchased ZXW Tools from our vipprog online store have no clue how to set it up?  Well, here is a quick guide detailing the installation process. Step 1 Unbox the ZXW tools dongle and plug it into your Windows PC.  ZXW tools does not support Mac at this time, so you’ll need a Windows compatible box. Step 2 Download the ZXW Tools software [direct link].  The ZXW tools website is in Chinese, but lucky for you, we’ve made it easy for you to download the latest version of their software directly from our website.  The zip file contains all of the files necessary to run ZXW Tools (trace) and Blackfish (schematics).  There is no installation process.  You just need to copy the files over to a directory on your desktop. Step 3 After you’ve copied all of the files over to a folder on  your desktop, then just run the ZXW tools executable.as shown in the picture. When your first run the software, the program will ask you if you want to activate the dong
Read more

IPhone 6P Front Camera and Distance Sensor Fault

Image
Received a iPhone 6 Plus, the customer said that the front camera can not be used, and the distance sensor has problem too. The two failures are concentrated on the front camera flex cable, which is likely to be caused by the damage of the wiring. First, we have to eliminate the possibility of the external parts fault, then consider the motherboard problem. Remove the screen assembly and replace it with a good one, we still can't turn on the front camera and use the distance sensor. Disassemble to measure the ground resistance of the front camera seat of J1111 by Fluke digital multimeter , it is found that several pins are infinitely large, and the related inductors are loose when touch with the pen. It seems that the small components are pseudo welded. 19-1- 1 Remove the motherboard and observe it under the Trinocular Stereo Microscope , we can see that the touch was repaired before. 19-1-2 The back of the sub touch chip U2402 is the front camera seat J1111, an
Read more