Xdj 1000 mk 2 sound quality

Hey people I have 3 xdj1000 mk 2s and for some reason my 3rd one the sound quality isn’t any where near as good as the other two it sounds distorted and even isn’t showing the same on the levels when I play All the same track and compare. I’ve changed all the rcas and even tried them on all different channels and that one xdj is just putting out less of a signal it’s like the sound out put is 3/4 of what the other two are .. it’s only about two months old