I have a Relisys LCD TV, model LV87E, but not the user guide. There's a mini-jack (I think) connector on the back which I can't identify: Not the 12V DC input but the other one. The symbol suggests that it's another input, but what could it be for? There are already phono inputs for AV1 and 2, which cover audio, component, and composite video. Any thoughts will be appreciated. Many thanks. Bert .