Charge Port Microphone not working after Power button flex replacement

Iphone 5, Verizon carrier, 16gb, black. IOS 8

Replaced the power button flex and about a day after the repair the phone's microphone that is used for calls stopped operating. Tried a new screen, new charge port x3, new power button flex x3 with no success in repairing issue. Tried soft reset.

Also did a board swap where we swapped the logic boards only from a good working iphone 5 for verizon. The microphone did not work even when we did the board swap with a good known phone.

A - bad mic phone

B - good mic phone

A with B's board = good mic

B with A's board = bad mic

Any ideas?