Soft pulley on Numark MP102, DJ CD/MP3 pitch shifter
 

Just a perished band for the tray drive ,only 5 years old, but query
about the first driven pulley after the motor pulley. Heavy brown
staining of transluscent plastic, presumably plasticiser leeching from
the drive band. But was the original pulley floppy, as though it was
made of rubber or gone soft from plastiser action? Motor only runs
inserting or ejecting a disc, and in a DJ environment why would you want
low audio noise from the motor system, if deliberately wobbly ,
vibration damping plastic for that pulley? As long as the replacement
band is not too tight(causing that pulley to bend and jam against the
deck) the tray is back working.