I had that as well, erm maybe due to some faulty cables.
Now I don't seem to get 'em anymore.

to trouble shoot and determine if cables are faulty, disconnect all cables leaving just the power cable on. do not link any of your eq's at the moment.
turn on/off everything and check, then work your way till the last cable one by one and see if those cables are causing the problem.

If you get the static even without interconnecting your eq's, then you should be able to pin point out which device immediately.

Happy testing bro. & make sure you off everything before connecting any thing just to be safe.