iPhone 6 Speaker Failure- logic board repair solution

The iPhone 6 has speaker failure, the detail is the iPhone 6 speaker doesn't make any voice when the iPhone in speaker mode. We tried to fix it by restarting, updating and restoring, but the iPhone speaker is still not working. Now we need to check iPhone logic board.

Use phone opening tools to disassemble the iPhone 6, first we need to check iPhone charging port. Measure the the resistance values of 1# and 2# on the flexible cable connector of the charging port by digital multimeter, the data tested is normal.

Next we need to measure the resistance between 1#J1817 and ground, 2# with digital multimeter , the value of current is normal, which indicates the circuit from the charging port connector to the U1601 is also normal.

Now, remove the iPhone logic board, measure the power supply voltage of the U1601 by DC power supply, the voltage is lower than 500, which is abnormal.

Put iPhone motherboard on the iPhone PCB holder fixture, put them under the microscope, and then remove the U1601.

Now, measure the resistance value between A6# of U1601 and ground, the value is normal. Continue to measure the resistance between A2# and ground, the measured value is "OL", A2# and B2# of U1601 are connected to the positive pole of the battery through L1604. Now we judged L1604 is the fault part.

Use Tweezers to remove the L1604, and install the new one, now the data tested is normal.

Apply some solder paste to the U1601, and then use QUICK 861DW hot air rework station to solder the U1601 back to the iPhone motherboard.

Assemble the iPhone 6, after entering the IOS system, test the iPhone speaker,now it works good. Continue to test other functions, all works properly.