CDJ 2000NXS 'Screeching Noise'

Hi guys, 

Recently out of the blue, my one CDJ 2000NXS has started to make a really high pitched screeching sound, I've narrowed everything down to the CDJ (ive changed cables/ mixers/ speakers etc)

It seems to happen whenever I plug the 'red' RCA cable into the back of the CDJ...

Has this happened to anyone before?