Calls and audio messages can only be made via loudspeaker

My wife’s Fairphone 4 fell off. We changed the display (gap) and the selfie camera (broken). Since calls and voice messages can only be listened to with loudspeakers, we also changed the earpiece. Unfortunately, that didn’t help.

We ran through the internal tests, and during the following three tests

  • Receiver discrete test
  • Speaker2 melody test
  • Mic 1 to receiver
    nothing could be heard, so something is broken.

What can we do to get my wife back on the phone normally? Thanks for any help.