Reply to S4 Not working!!??

Ive heard my traktors for about a week now and they been working fine. Today i turned them on connected everything up and they dont seem to want to work.

The USB light is on and my computer recognises it and so does Traktor software. And when i play a song on traktor it comes through the audio speakers which are attached to the S4. This is very annoying and any help would be appreciated. Ive attached some pictures aswell

Thanks