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The Best Solution to Fix iPhone 6S Plus Audio Fault

Received an iPhone 6S Plus last week, according to customer's description, it's audio fault, the device was fixed before, but the same fault still exist. After accepting it, the first stop is to measure the audio parts, the original iPhone audio is not measured with large current, but in the contrary, a new audio IC shows large current, so we can determine that the original iPhone audio IC is good.

Connect the iPhone device to check, it is not available for recording but the ringtone is normal. After disassembly, we find that large audio was not replaced before, first we are going to clean the iPhone motherboard. The electric current is normal when booting, the resistance measurement of U3500 M7 pin is on the ground. the point is the main power supply of PP_VCC_MAIN, if it is grounded, it will certainly clamp large current, so once again when we pinch, large current is not there. As shown in picture 8-6-1.



Remove the shielding cap to measure the capacitors C3603 and C3601 near M7, we also found that the capacitance is measured to ground. Remove these two capacitors to measure U3500's M7 pin and C3603, C3601 resistance is infinite, and now it can be sure that the wire is broken. Measuring M7 pin and capacitor is the same, soldering the jumper wire from the capacitor C3603 to the nearest PP_VCC_MAIN, from the picture 8-6-2, we can see that the point of which more convenient to borrow power is the capacitor C4020.



Finally, apply UV green oil to fix and insulated, the resistance of M7 is returned to normal, and we do the clamping test again, the current is normal, so we install the iPhone 6S Plus to test functions. As shown in picture 8-6-3.



 Finally, all of the audio, transmitters and receiver functions return to work now!

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