Reply to S2 mic engage broken? Any ideas?

Pretty simple. Used to work no problem. Simply will not let audio throught. You can vaguely hear mic noises when you power up the unit, but then back to silence.

Bought used, not going to try to messing with NI, guess I'll just be plugging/unplugging from one of my powered speakers if I need to use a mic. Not terrible, cuz I hate using it anyhow, but the manager at my gig last evening said I'd need one. :/