MPC1000 feedback humming noise

So ive been searching for answers for a couple of hours and nothing is helping so heres my setup

Rane mixer w/ 2 turntables going in both phono inputs
RCA going from L/R of Line 1 Rane Mixer to L/R sterio out on MPC1000.

I get noise from both L/R on my MPC to my mixer so everything is getting sound and seems to be setup properly.

Problem is theres a humming/feedback sound coming through the speaker constantly. The noise happens when the MPC is turned off as well (stops when I unplug the MPC though). I tried new cables and still happening.

I've tried wiggling the inputs/outputs on the back of the MPC and I get a humming noise on each one of them.

Can someone help me out here? I may possibly have something set up wrong but im in need of some help!

Appreciate it!

Edit: this can be made less apparent if I turn the volume down on my reciever to my sound system and up the volume on the MPC itself. So I dont hear it if I turn down my recievers volume and make my mixer and MPC louder. But it's still there.

Search for: Ground loop.

There is no cure, might as well smash your shlt up. NOW.

I had ground loop hum even when my MPC1000 was turned off. The culprit was a midi cable connected to the midi patch bay. It had the outer shielding connected to the jacks on both ends.