PC Engine AV Cable

[zenji]

Hi I need to make an AV cable for my DUO-RX.  I have looked at the pinouts at GameSX but I do not know what is connected to +5v (pin 4) and Ground (pin 3).  Also where are the Left and Right Audio sheild wires connected, is it the outter sheild at the din end of the cable.  

[NFG]

Shield (not sheild) is Ground.  If you don't need +5v, then don't use it.  

[zenji]

So the Left and Right Audio shield wires are connected to the outter shield at the DIN end of the cable and +5v (pin 4) is not used.  Am I right?  Then what is Ground (pin 3) used for?  I think its the Video shield wire.  It would be useful to know before I proceed.