What is this chip marked CD on it?

My MacBook just switched off and then there was this burning smell that came. I took it to the service center where they said that a component on the logic board has got loose and that they will not solder it back as apple only replaces the component. Now the entire motherboard would have to be replaced is what they are saying.

Can anyone tell me what this component is which has “CD" marked on it and if I can purchase this from somewhere or maybe if this could be fixed somehow.