Reply to S4 consistant audio stop start

In need of some help. Went to have a play on my s4 today (its been a while) plugged it all in but when i hit play the song stops and start at consistent speed, it will play approximately 1 bar and stop for about 1/4 of a second, over and over again also the audio coming out is unrecognisable its just a scratchy mess.

If I play around with the latency settings I can get better audio quality but the stop/start thing is still there.

Songs play normally in traktor without using s4 so I suspect it is s4 hardware related?

Could it be a usb cable thats gone bad? (dont have another one to test it)

have just done a complete uninstall, reinstall, made no difference.

Installed snuko (mac theft software) the other day, maybe this is making it play up? I cant delete it as I have to log online to do so and my passwords not working for their website! Grr

basically a brand new macbook with no junk on it, traktor load levels are very minimal

does anyone have any ideas?