Hello. I have a CE4000 that is out of warranty, that when I plug into a GFCI outlet it trips the GFCI. When I do outside gigs I kept having this problem, and traced it down to this amp. I am guessing it is leaking power somewhere and not returning all the current back to the neutral, then because of this tripping the GFCI outlet. Has anyone else had this issue? How could I go about trying to find the problem? The amplifier itself works fine on any regular outlet. Thanks.