I found this little fix after contemplating cap replacements. As it turns out the Headphone socket has an electrical interlock with the return path to the speakers. It switches the ground to the left and right channels when the Headphones are plugged in. This is a real weak point for boxes and can be easily bridged out if only to eliminate issues with these contacts. Below is from a Sony mini that has a Headphone on top so could easily fill with liquid and dust and corrode the contacts.
