Is it possible to repair or replace a digital coaxial input? I have a Pioneer...

[JoeeR]

...xv-htd520 home theater surround? system that I bought back in 2000. It cost $500 at the time.
I was very happy with the performance and sound of this system until the digital coaxial input stopped working recently.
I now get no surround sound from my Playstation 3, which is hooked up to this input via a Coaxial to Optical Digital Audio Converter box.
I tried changing the settings on the Playstation 3 to output my surround sound to this input, but nothing happens.
I've tried moving the wires, and pressing them against the digital coaxial input, and sometimes you hear sound through the speakers for just a brief moment, which leads me to believe it's a mechanical problem with the input, rather than a problem with the settings.
I've tried Googling "how to fix a digital coaxial input", but I get nothing.
Is there a way I can fix this problem myself, or have it fixed inexpensively? I am not in a position right now to drop $1,000+ on a new home theater system, and I would be happy with the one I have if only this input can be repaired.

 

[TheEagleKeeper]

That's a very dated unit you have there. If you have a PS3, then I would go ahead & upgrade to a receiver that can decode the latest surround codes. I attached a link to a good receiver. I have one just like it. It's only downside is that it has 2 HDMI inputs. But it's a killer reciever with lots of high quality & expansion options like iPod, second room, external amps, etc... You don't have to buy new, just a good used one is all it takes. The same amount of money you spend fixing the old unit, you can buy a half decent up to date model. It too has plenty of coax & optical inputs. Good day Sir.