That makes sense. Two of the jacks are Line IN and Microphone. Those are input jacks and not outputs.
Bob
I don't get sound out of every jack in the back of the card for some reason...I only get sound out of the Line Out 1 jack...that's the 4th plug counting from the IEEE plug...there are two others in between, Line Out 2 and 3..I have one set of spearkers (built into the SONY LCD) connected to line 3 and then have 4.1 speakers connected to either line 2 or 3 but neither work..they worked before...when I freshly reinstalled windows..it does not work under linux either...I don't know why it works on and off like that...any suggestions?

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