My pionner Ddj Sb2 have a noise in OUT máster (RCA) and is perceptible and high while music is playing

Hi. I have noise (all the time) in OUT (RCA) máster. And in live session is horrible and incofortable. I'm soynd technician. I put D.I for OUT (RCA-JACK 2 mono) and selectioned OUT earth and lift and the sound (noise) persists. It's doesn't change. Y try with others PCs, and wires, and usb, and the noise continues. If If I remove the negative pole the noise is gone. So...What do you recommend? Thank you. I need It because I have a shows Next days.