http://www.axiomaudio.com/troubleshooting_ep500.html#

click on the link and then click on the link that says View Chassis Ground Screw. I know this is the amp for the EP500 but the ground screw should be similar on your EP800.

I would also unplug the sub from the outlet when doing this.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne