I recently recieved a beautiful old Cambridge Audio P100 from a relative who passed away, and it's got a couple of problems, the most notable of which is that when headphones or speakers are plugged in, audio only plays over one channel, usually the left, although this can change. I'm totally new to modifying and repairing electronics, so I'd feel a little daunted by the prospect of cracking it open and having a look. Is there some way to perhaps remedy this externally, maybe by cleaning the contacts on the headphone-out and aux-in with a t-swab, or would that damage it further? Any help would be appreciated. Thanks in advance.