I have this SB Live! model CT4620 with issues with the right stereo channel.

It's way more quieter than the left one and the most odd thing is that if I move L/R balance level to full right side then only the left channel can be heard.
I will try explain better. While I move between the center and the right side I can hear both channels and the left goes quieter but then when I reach the 100% right then left speaker volume goes up again and right doesn't output nothing at all.

My hopes that is something fixable are low, I tested the card in two different PCs with different OSes and the behaviour is the same.
And I don't see any bad caps or connections but here are the photos.

EDIT: The faulty jack connector would be the most obvious thing, but it's clean inside, still lubricated it and used different cables. And also it wouldn't explain the odd L/R balance thing.