I upgraded premiere yesterday and lost my volume control (the slider bar). It could very well be a coincedince but I've looked through the menus, keyboard shortcuts and prefrences, I've also searched google and cant find an answer.
I believe it's the white line between your channels.
It moves up and down and changes the volume.
Right-click the little FX (top left of the clip as in the screenshot) and select "Volume/Level"
Great find, it was set to bypass. Thanks!