Why my m-audio fast track pro doesn't pick up any sound on garage band?

I have a m-audio fast track pro and I have always recorded on it. be it using a mic or an instrument. Now Im having a lot of problems with it. It doesnt pick up any sounds when Im using it. And I have checked the input and output settings on preferences. And when I play any real track intruments through it the sound comes out all distorced and metallic. Midi sounds fine. Does anyone knows how to help me?