How would one go about finding out if a microphone is good or bad? The one in question is a "Low Z" Shure.

We got an intercom system that someone else thinks has a bad amp. Before changing out the amp I decided to try the mike on a different amp and it did not work so I suggested we get a new mike first.

The above was somewhat longer to actually do than explain, so if there is a better/faster way to do this, can someone let me know?

Thanks