Every cable coming from the front panel I've identified except one. It is a cable with three wires colored RED-BLACK-VIOLET. It has a 3 pin connector on it. I've traced it's origin back to the display board. I suspect that it is a power supply connection. There is no mention of it in the manual or shown on the schematic drawing which was inserted separately in the manual. Not knowing what it is, I will simply ignore it, but I am curious about it.