Well, there are two problems: a) a defective micro USB port (or a non-charging FP2), b) a defective microphone. The vibration motor and the speaker seems to break not so often.
You could build an intact bottom module from two if one has a broken microphone/micro USB port and the other has a broken vibration motor/speaker.
I have opened a support request (#148419) to get an official answer when the bottom module is available again. (Why does sending a support request only work with Internet Explorer, but not with Firefox? → #148466)