No voice call microphone function after screen replacement?

Hi,

I replaced a screen to a P9 and everything else works fine but the main voice call microphone. Even the secondary mic on top of the phone is fine.

Anyone else have had this issue?

The phone chassis was badly damaged and had to change that also.

I have tried:

• 2 different spare part mic/usb daughterboards
• different flex-cable from motherboard to mic/usb board
• factory reset

I could not test the mic functionality when the phone came in as the screen did not work.

There are ground pins on the mic/usb board that supposed to connect to the chassis goldplated parts. Maybe they are not getting connected and that would be the issue?

Any help would be much appreciated.

Thanks!