[RWebb]

It will fit if I move it to the left, and skip the pin below the "f" where the label says On/Off - then the blocked-off spot on the connector fits down into the open hole on the plastic board receptacle.

But it seems weird to do that & I don't want to blow anything up - I can't find any other place on the mother-board where this connector will fit, also "On/Off" makes sense. Pixxo, the case manf., doesn't have any documentation on it that I can find.