Why is my mic not working?

@napoleonmapana start off with checking things that Samsung recommends

Try using the microphone in safe mode. If there is no problem in Safe Mode, it may be a problem caused by an installed third-party app on your phone. To find which app is causing the issue, you can try uninstalling the apps in the order of the last installation.

Step 1. Open Quick settings. Tap the Power icon at the top of the screen.

Step 2. Touch and hold Power off until the Safe mode icon is displayed.

Step 3. Tap Safe mode. If you've entered Safe mode successfully, you will see Safe mode displayed at the bottom of the screen.

If the device works in safe mode, an app is most likely causing your issue. Remove recently downloaded apps one by one until the problem is fixed. If the problem persists when your device is running in Safe mode, the problem might not be related to an app.

To exit safe mode, restart your device.

If that does not work for you it may be time to replace the mic. The mic is mounted to the charging board (Charging Connector Flex PCB Board). Replacing that should fix a broken mic. Use something like this video to replace the board.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!