i have a 5800 that stopped working. after many hours of cussing and pulling wires i figured out that when the remote shut off wire is connected it automatically shuts off. this is regardless of whether or not preamp is on or off. the second you put the wire in the hole amp shuts off. easy fix is run power cord on a switched plug or just turn off and on manually, but does anyone know why this would just all of a sudden do that?