I know the cable isn't actually superglued in - that was sarcasm because the cable was so difficult to remove.
Look very closely at the picture - the motherboard connector pins have lifted slightly away from the motherboard.
If I use a toothpick to press down on the leftmost pin (the one to the right of the "4"), the right speaker sound works again. It looks like it's lifted off the board. However, I don't know to what extent it's lifted.