How to fix iPhone 7 with a faulty audio codec

Максим Исаев
Reading time: 2 min

Repair sequence for iPhone 7 with a faulty audio codec

Today we will consider an iPhone 7 repair with a faulty audio codec, which we carried out on the BGA soldering training.

After repair in a third-party service, a client brought iPhone 7 in Bgacenter with problem: all microphones do not work and speakerphone in a call mode does not work also. In the photo below, it is highlighted that the speakerphone icon is not active.


iPhone 7 Audio codec repair sequence:

First, we raised the display module, for subsequent disassembly of the phone and prepare the motherboard for diagnosis and repair.


After that, we soldered the U3101 chip and performed the measurements with a Fluke multimeter.


Specifically, we measured the voltage drop on the twelfth row of the contact platform, where the u3101 chip was previously installed. The drop in voltage was compared with the obviously serviceable “donor” board. No breaks were found.

This is a weak point in the iPhone 7 and most often the broken sound system is the result of a fall or deformation of the case. This is due to the design feature of the iPhone 7 motherboard.



We have prepared u3101 chip for replacement using copper braid to remove solder, flux and soldering iron. We took CALTRA AUDIO CODEC from obviously serviceable “donor” board.


Then we made installation of an audio codec on a board, in addition having corrected braid damaged in another service.




Then we assembled the phone and conducted a rapid diagnosis, checking the sound system using the application “voice Recorder”. Recording works. Great!


And we additionally checked the Hands-free mode by calling 112. The icon became active and began to switch modes.


Now the iPhone is working.

What tools were used

The following tools were used to diagnose and repair iPhone 7:

  1. Pentalobe screwdriver 0.8
  2. Three-blade screwdriver 0.6 mm (Y)
  3. 1.2 mm Phillips screwdriver
  4. Screwdriver for iPhone
  5. Suction cup for lifting the display module
  6. Separator LCD SEPARATOR SCOTLE PR-1000
  7. Fluke Multimeter with Ultrathin Probe Kit
  8. Professional microscope (40x magnification)
  9. Induction Soldering Station Metcal PS-900
  10. Stencils, braid for solder removal, flux (FluxPlus)
  11. SolderPlus Solder Paste
  12. Dongl ZXW Software


Diagnostics and repair of the iPhone 7 audio codec took 40 minutes.

The cost of such repairs is about 4 000 rubles.

The duration of training in diagnostics and BGA soldering, on professional equipment at Bgacenter is 8 days.

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