Problem with my sherwood

I have a Sherwood R-925RDS, no matter what input I use I have a constant 120hz buzzing noise and no actual output of music and when adjusting the volume it outputs a clicking sound, I've narrowed down the problem down to the between input and preamp (including preamp), I don't know much about A/V receivers and I'm completely lost on possible solutions, what's anyone's suggestions (here's a link to a video of what I mean)