iPhone 8 has no sound repair

Failure model: iPhone 8
Malfunction: There is no sound or vibration in the mobile phone.
The customer described that there was no sound or vibration when the machine was in use, and it was accompanied by runs slow.

iPhone 8 has no sound repair Figure 1.

Fault analysis: There is no sound from the external, and the vibration function can’t be used. The machine is still runs slow. Generally, this kind of fault is caused by the problems of coder IC chip, and the machine has not been dropped, which is the phenomenon in use.
Maintenance process: get the machine, test the function, and there is no sound or vibration when it is put out. When the bell is clicked,runs slow will appear. The problem occurs in coder. Remove the machine, take down the motherboard and coder IC. Please note that PCB layer of this machine is easy to disconnect and cause Low current to start, so pay more attention to wind speed and temperature.

iPhone 8 has no sound repair Figure 2.

Remove coder, measure that diode value on coder IC PAD is normal, and install a new coder IC.
Maintenance result: during the installation test, the external sound and vibration returned to normal, except runs slow, and the function was normal. The maintenance ended here. This fault was caused by the damage of coder IC. Replace coder IC to return to normal.