KB4000

My Cinema 800 isn't doing so hot. DSP shows 0.0 and numerous attempts to flash it have so far failed. It still shows 0.0 after update and doesn't play any sound. I noticed the sub has an LFE Input and output jack on the back so I figured I could at least keep using the sub if I can't salvage the sound bar. The manual doesn't acknowledge these jacks at all, so maybe they don't work. I have plugged into the input jack but don't get any sound from it. The light switches from blue to green when something is actively plugged into it, but no audio. Can someone with a Cinema 800 try using their sub this way with the sound bar off to see if it will work? If not I may take the plate off and use a different amp as I think this sub sounds pretty good.