Original post by: Brendan Peterson ,
Hey guys i found a fix for the mic problem IF YOUR PROBLEM IS HARDWARE RELATED. So through some research I saw that the problem is that the Qualcomm WCD9335 audio codec chip located on the back of the motherboard has a tendency to have some of the solder joints disconnect and cause audio issues. I found a fix but its a little bit of work. So you basically need to reflow the solder on the audio chip to restore the connections. I accomplished this by removing the motherboard from the phone and heating the entire board for about 30 secs with a precision heat tool and then covering the board with foil except for a cut out where the audio chip is located. I heated the chip for another 20 secs and then waited for the board to cool down to room temperature before reassembly. So far it seems to have worked, its been about a week. I used the tear down of the google pixel XL as reference when I did this. NOTE: DO NOT OVERHEAT THE BOARD, USE MINIMAL HEAT AND GO SLOW!