Chosen Solution

Hi there, I had a problem because my iPhone wouldn’t charge anymore when I plugged it in, so I replaced the charging port (along with bottom microphone and headphones jack). After replacing them, I noticed that when I plug in my headphones, their microphone doesn’t work. Instead, the bottom microphone of the iPhone is the one which works. Where does this problem come from? No other issues detectable!

It could just be a defective replacement Lightning port. Re-install the original (just overlay it) and try the headphone port. If the original still works, then the problem is with the replacement flex.