mic noise

hi when i switch on my mic switch on ddj 1000 i can hear some white/crackling noise until i turn mic switch off ....but for some reason i can tap/whack controller near the jog adjust button and it stops till i turn mic switch on again ..it overides the music. I still get the noise even if no mic is plugged in.

ive also changed mic lead and purchased new mic but still happening

quick vid

https://www.dropbox.com/s/h6luksywiq2i0ou/Video.mov?dl=0

Thanks in advance