Dvd player makes humming sound while playing...

Question

a dvd fell off of the tray inside player and got it stuck so i took the cover off and removed the stuck dvd. all the mechanics seemed to be working so i put the cover back on and played a dvd. The video seems normal but there is now a buzz that varies in volume according to what is playing and what is the primary color on the screen. (red seems to make it the loudest.)