The subwoofer on my promedia 2.1 system has stopped working. Or I should say that it's not connecting. I have had to jiggle the plug into place for it to work, but now that won't even work. Is there a way to fix this, or do I need to look into a new set of speakers?  I have had these speakers for about 7 years, and have had connection issues on and off, but now it's very very irritating that the woofer won't work.