Why is my microphone not working?

Once, I regretfully allowed a friend to borrow my op-1 for one night, I got it back and the microphone no longer works and two of the knobs are missing and one is bent. Other than the microphone, the only other issue I have is that when recording music and listening to it there is a crackle like an old timey radio, this is cool for some things but not when you want clarity of sound. I downloaded it onto my laptop to see if it was just the speaker on my op-1 but it was still there on my laptop. Please help.