I had the same problem 4 months ago. I took it to a local computer repair (mom & pop type) shop and they fixed it for me overnight. It was, indeed, the jack. It cost $115 and it's worked beautifully since. They also told me it's a tedious repair and that's why many places won't do it.
Thanks for the info, I guess I will call around. I know I'm not brave enough to try it myself. Hopefully, I can find someone not too expensive. $115 is not bad at all.
Does the jack need replacing or will soldering do the trick by itself?