We've discovered a "signature fault" in the iPhone 7 series which results in no audio meaning no sound from the ear speakers, loud speakers or microphones. Occasionally this also triggers boot-loops, which is when the phone tries to turn on a fails the hardware check which causes the phone to reboot for an extended period of time.
Read MoreIn order to determine if the Tristar IC is functioning properly, test the voltage of the battery terminal--after you confirm that the phone is pulling amps using the ammeter
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