another one? we just had a blown aux jack thread not so long ago. do some search on it, you should find it.
also, having JBL myself, and now using that jack for streaming, keep in mind that really have to crank volume up to hear anything. it's some sort of high resistance or whatever input, so whatever you have plugged in must be roaring into it.
clean it with electronic parts cleaner. if it was never used, it prolly oxydized. then stick jack in and move it back n for sevral dozen times, just to clean stuff off.
btw, this thing works very well with original JBL:
http://www.movinondealers.com/Catalo...44/page44.html