No sound from headphones

No sound from headphones

Im using traktor 2 with the kontrol s4 and when i hit the cue button there is no audio from my headphones. Everything was working fine until a couple days ago but i didn’t change anything. Also sometimes my laptop will shutdown while using the s4? (usually about 20/30 mins after i start) and when i start it back up there is no response from the s4.

Any help would be much appreciated.

Where do you have your audio coming out of? Laptop? S4 or some separate soundcard?