iphone7 screen does not display

Received a iPhone7 from one of our customers. The fault described is that it can enter the system and the customer can hear the message voice, but the iPhone screen does not show anything but black. As shown in picture 1.

Pic 1


Connect the adjustable DC power supply, the current shows all normal, and it also respond when connect it to the computer.

Disassemble the iPhone 7 motherboard to measure the basic conditions of the display function by Fluke digital multimeter, it's measured that the seventh pin PP_1V8 of  touch socket(J4502) display power supply at infinite value, now the fault is found.

Pic 2


The power supply is changed from PP_1V8 to PP1V8_LCM_CONN by inductor FL3906 conversion. The end of the inductor has resistance value, and the other end has no value, so we judge it's FL3906 damage.

Connect the jumper wire as shown in picture 3.

Pic 3


Failure is repaired successfully!

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 yo...
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