MPC 500 left Input not working

I recently bought a used MPC 500 from guitar center. Everything seems to work as it should but the left input. When I go to sample it picks up a stereo signal but not a mono L signal at all. When I use headphones only the right ear plays sound and the left makes this noise/static. I use a trs y cable that I use to sample with my mpc one + and that works fine so I know it may be the left input of the mpc 500. Any ideas on a fix or what I should do?