iPhone 6S Plus calls no sound energy, fast fault repair

Machine model:iPhone 6s Plus
Trouble symptom: the phone call is silent, the sound cannot be recorded, and the music can be played,battery die more quickly.
Maintenance process:
Received a iPhone Plus, fault description. After falling during use, the phone battery die more quickly, no sound when calling.
Connect DC power supply motherboard short-circuit current with more than 50 mA, enter the system for testing, and turn on the recording function in dark color.

iPhone 6S Plus calls no sound energy, fast fault repair Figure 1.

iPhone 6S Plus calls no sound energy, fast fault repair Figure 2.

According to the above picture, we know that microphone has a fault, and analyze the fault according to Boardview and drawings.

iPhone 6S Plus calls no sound energy, fast fault repair Figure 3.

iPhone 6S Plus calls no sound energy, fast fault repair Figure 4.

iPhone 6S Plus calls no sound energy, fast fault repair Figure 5.
Measure these two points to U3500(coder IC) and diode value to the ground as OverLoad. Unhook the sticker on the back of the motherboard and find that U3500(coder IC) has been damaged, resulting in battery die more quickly, which can’t be recorded and the caller can’t hear it.