How to restore sound card to default on late 2012 mac mini??

Question

I have a late 2012 mac mini with a sound card that is not working right? The issue is the line-in is not working at all, and the microphone is grayed out, like its disabled?? Please Help!!!

Answer 1

The only ways any Mac Mini could have a microphone, since there is none installed:
1) if you have a display with built-in mic; or
2) have an external camera, with built-in mic.
An iSight camera, original FW400 model, has a built-in microphone. Some Cinema
or wide displays with their own speakers and extra ports, may have a built-in Mic.
A newer Thunderbolt 27-inch or 27-inch LED Apple, has built-in iSight or facebook
kind of camera and those include a microphone.
So while nobody doubts a microphone would be necessary for a local voice input to
a Mini Mac; there is no reasonable doubt of built-in mics, as no MINI model had any.
With that off the table, the other information already presented is worth revisiting...
A reset of the SMC/PRAM may help an actual hardware or software (firmware) issue;
but, it cannot reconnect with a non-existent 'built-in' accessory where none is present.
The system profile hardware information in the Mac OS X will show all the components
and their software aspects, as does most published information on the entire Mini line.
If a reset of the System Management Controller, or Parameter Random Access Memory,
fails to change the situation, try both of them again. Carefully & deliberately. And then,
if there is no traction and the peripheral aspects of other accessories which would be
most likely to include built-in audio input are also double-checked for function, you may
choose to inquire of an expert, product specialist, Authorized service provider, etc and
have them perform tests to see if there is some other hardware failure involved.
Good luck & happy computing!