Chosen Solution
My screen broke, I bought replacement followed the guide to take phone apart, put it back together and microphones stopped working. If I connect the headset with mic/headphones it works but not without it. OnePlus is quoting me $185 USD for repair along with S&H two ways and possibly duty charges. Any way to figure out what went wrong?
You could always carefully disassemble it and check all the connections. It is possible that the mic became dislodged or damaged.
My friend you have to change the motherboard is the only way to fix it, cuz the microphone flex connector was mixed
