firstly it sounds as if your son may have caused some damage if something is rattling about you need to open the unit to see what is rattling if you dont see anything amiss then unplug the unit and supply a 9v battery to the motor that drives the laser mechanism forward and back to confirm it does if so then pop in a cd if you hear the assembly move into position then remove cd clean the laser with isopropyl and also a little bit of morton grease along the track that moves the laser into position these units are prone to not reading cds
joe
March 2019