How To Fix iPhone 6 Loudspeaker Not Working

Malfunction Phenomenon

When playing music or setting the ringtone, there is no sound from the phone.

Trouble Shooting

1. Run cosmetic inspection of the charging port connector J1817, nothing goes wrong.
2. Run diode mode measurement of J1817, the measured value of Pin 1 and Pin 2 is abnormal.
3. Pin D2 of the audio amplifier chip U1601 is connected to Pin 1 on J1817 by way of R1603, C1663 and C1602. Pin C2 of U1601 id connected to Pin 2 on J1817 by way of C1600 and C1660.
4. Run diode mode measurement of components on the two rails. Judging by the measured value, C1600 and C1660 have shorted.
5. Remove C1660 and C1600 and run diode mode measurement of the two pads. The pad under C1600 is shorted. Remove U1601 and measure the pad under C1600 again. The measured value is normal this time. We can confirm now that U1601 has malfunctioned.
6. Continue to check the rail related to Pin 1 and we find that C1602 is also shorted. Remove C1602 and run diode mode measurement of its pad. The measured value is normal. Which indicates that C1602 has also malfunctioned.
7. Replace C1602 and U1601. Problem fixed.