My protools mic won't work. Someone help?

I've been using protools LE 8 for about 6 months now, and I've had numerous technical difficulties with it, the most frustrating of which is that the mic won't work. The mic has worked in the past, with very little trouble, but all of the sudden it has just stopped and i'm wondering if anyone knows why. I plug it in to the box (Mbox2 mini) and then I press record on a track, I've made sure that I have the correct input and everything, but nothing heppens. I've tinkered around with it a little and when I press th 48V button, mic/di button or anything else on the back, all I get is a weird popping sound in my ear phones, and the volume indicator next to the track will bounce from the red to the green before going back to nothing again. I've had this problem in the past, and just rebooting protools has worked, but now nothing seems to help. I don't want to waste another ten hours reinstalling it, and I don't want to buy a new interface. If anyone has any advice, please tell me.