Quote Originally Posted by GeddyLee View Post
If you are still getting that noise out of HU, more than likely the piezo* fuse inside the HU blew. I am misspelling the name of the fuse, but it is something that can be only replaced by a professional or sent back to company to be repaired.

I have a Pioneer 6000 HU and it had some serious ground noise issue and I fixed it by doing this........



I believe you mentioned that you tried this, but with no success? I am not sure if you set yours up like mine, but if you didnt? You might want to try and do it like I did to mine. It worked WONDERS!

If that doesn't solve it, I would say take it back or get another HU unfortuately
WOW FREAKIN AMAZING this worked AMAZING I can't beleave it everying works perfect now and it sounds better than it ever did before I tried to fix this on and off for the past 8 months