HDJ-1000's

So I had mine about 9 months and for the last 4 months the sound cuts in and out and sometimes bass is there and isn't. I really have to fiddle with the end jack that plugs into to mixer for it to work and leave it at a certain position but if it moves slightly I have to do it all over again. It's a real pain. Is there an easy fix or do I have to send them in?? I already sent them in once and had to wait a while would rather not do it again.