Why the mic volume has static sound?
There is a loud continuous static sound whenever the volume of the mic input is turned on.
I'd check the connectors on your cables first and make sure they aren't fouled up. Maybe swap out the cable and see if it gets better.
Is this a wired microphone or wireless? That would help us better identify the problem. If its a wireless microphone start by replacing the batteries in it, they're notoriously picky