Bottom mic not working
Has anyone seen a mother board issue cause the bottom mic not not to work. I have already changed lighting port assembly twice
Has the phone ever been repaired in that area? Maybe the charging port assembly was removed/replaced and wasn't installed correctly and the mic is being blocked. It also sounds like there could be dirt/dust in the mic hole which would cause it to not pickup sound or sound muffled.
Is it possible there is some sort of cover over the mic . I just fixed a phone that had a blue tint to the photos it took and it turned out there was a protective film over the inside lens direct from the factory . Is it possible theres some sort protective shipping cover over your new lighting port assembly?
If the connector where the charging port/mic connect to main board has debris it can cause the issue. Double check the connector.