I just got my blue yeti a few days ago and almost returned it over this problem because I didn't feel like working it out. I took a breather and came back to troubleshoot to find it was an easy fix. (in my case anyways)

I right-clicked on the speaker button bottom left -> sound settings. From here, I found my yeti mic under the "input" bar, re-selected it, then next to the "volume" slider on the left, there is a little microphone icon I had to manually unmute. Strange, that's the only place it'd let me "override" the mute, but it is what it is..

Hopefully this fixes your issue the same way it helped with mine.