Noise during recording and no FaceTime

Hi!

I changed housing of iPhone 7 Plus, replaced screen and battery. Now I have 2 problems:

• there is noise, buzzing sound that I hear when watching video I recorded. Previously there was not such issue.
  
• Facetime doesn’t work. This is very strange, cause front camera is working well, I can record video (without buzzing, noise is only with back camera) I can take picture. I also can make FaceTime audio, but not video. Only black screen and disconnecting after 1 second.

Did I damaged something? All replacement part were oryginal iFixit. What can I do? I restore and DFU phone, didnt help :(

Regards