Camera failure in this context would likely be solved by a hard reset (should be done on W10 update anyway). Mic failure is a hardware issue.
Lack of working 5.1 sound recording during video is an OS bug which MS have yet to acknowledge, but it should record in stereo. If not, then you will have hardware failure. I got this same issue. Microsoft did fix it (though they were not quick or convenient like Nokia used to be before MS closed down all their care centres here). Read about it on the 930 forums. It is certainly not the OS.
I made a hard reset, and it fixes some things. Microphone still doesn't work. Battery drained very quickly. OS wp10 still hang lots of time.... Sorry, i'm with pc, and xbox one and 360. But I give up with mobile..... Moving to Android